diff --git a/ApplicationLibCode/FileInterface/RifEclipseInputFileTools.cpp b/ApplicationLibCode/FileInterface/RifEclipseInputFileTools.cpp
index 6100bb1..43122c1 100644
--- a/ApplicationLibCode/FileInterface/RifEclipseInputFileTools.cpp
+++ b/ApplicationLibCode/FileInterface/RifEclipseInputFileTools.cpp
@@ -90,6 +90,24 @@ RifEclipseInputFileTools::~RifEclipseInputFileTools()
 //--------------------------------------------------------------------------------------------------
 bool RifEclipseInputFileTools::openGridFile( const QString& fileName, RigEclipseCaseData* eclipseCase, bool readFaultData, QString* errorMessages )
 {
+    QFile unitFile( fileName );
+    if ( !unitFile.open( QFile::ReadOnly ) )
+    {
+        if ( errorMessages ) *errorMessages = "Cannot open the grid input file.";
+        return false;
+    }
+    auto unitSystem = RiaDefines::EclipseUnitSystem::UNITS_METRIC;
+    auto unitPosition = findKeyword( "GRIDUNIT", unitFile, 0 );
+    if ( unitPosition != -1 )
+    {
+        unitSystem = readUnitSystem( unitFile, unitPosition );
+        if ( unitSystem == RiaDefines::EclipseUnitSystem::UNITS_UNKNOWN )
+        {
+            if ( errorMessages ) *errorMessages = "GRIDUNIT must declare METRES, FEET, or CM.";
+            return false;
+        }
+    }
+
     std::string filename = fileName.toStdString();
 
     auto objects = RifEclipseTextFileReader::readKeywordAndValues( filename );
@@ -169,6 +187,7 @@ bool RifEclipseInputFileTools::openGridFile( const QString& fileName, RigEclipse
         ecl_grid_type* inputGrid = ecl_grid_alloc_GRDECL_kw( nx, ny, nz, zCornKw, coordKw, actNumKw, mapAxesKw );
 
         RifReaderEclipseOutput::transferGeometry( inputGrid, eclipseCase, false );
+        eclipseCase->setUnitsType( unitSystem );
 
         if ( readFaultData )
         {
diff --git a/ApplicationLibCode/ProjectDataModelCommands/RimcEclipseCase.cpp b/ApplicationLibCode/ProjectDataModelCommands/RimcEclipseCase.cpp
index ba5df8c..aef9596 100644
--- a/ApplicationLibCode/ProjectDataModelCommands/RimcEclipseCase.cpp
+++ b/ApplicationLibCode/ProjectDataModelCommands/RimcEclipseCase.cpp
@@ -58,6 +58,38 @@
 #include <vector>
 
 CAF_PDM_OBJECT_METHOD_SOURCE_INIT( RimEclipseCase, RimcEclipseCase_importProperties, "import_properties" );
+CAF_PDM_OBJECT_METHOD_SOURCE_INIT( RimEclipseCase, RimcEclipseCase_gridUnitSystem, "grid_unit_system" );
+
+RimcEclipseCase_gridUnitSystem::RimcEclipseCase_gridUnitSystem( caf::PdmObjectHandle* self )
+    : caf::PdmObjectMethod( self, PdmObjectMethod::NullPointerType::NULL_IS_INVALID, PdmObjectMethod::ResultType::PERSISTENT_FALSE )
+{
+    CAF_PDM_InitObject( "Grid Unit System" );
+}
+
+std::expected<caf::PdmObjectHandle*, QString> RimcEclipseCase_gridUnitSystem::execute()
+{
+    auto gridCase = self<RimEclipseCase>();
+    if ( !gridCase || !gridCase->eclipseCaseData() )
+    {
+        return std::unexpected( QString( "The case has no loaded grid data." ) );
+    }
+    QString units;
+    switch ( gridCase->eclipseCaseData()->unitsType() )
+    {
+        case RiaDefines::EclipseUnitSystem::UNITS_METRIC: units = "METRIC"; break;
+        case RiaDefines::EclipseUnitSystem::UNITS_FIELD: units = "FIELD"; break;
+        case RiaDefines::EclipseUnitSystem::UNITS_LAB: units = "LAB"; break;
+        default: return std::unexpected( QString( "The loaded grid has an unknown unit system." ) );
+    }
+    auto result = new RimcDataContainerString();
+    result->m_stringValues = { units };
+    return result;
+}
+
+QString RimcEclipseCase_gridUnitSystem::classKeywordReturnedType() const
+{
+    return RimcDataContainerString::classKeywordStatic();
+}
 
 //--------------------------------------------------------------------------------------------------
 ///
diff --git a/ApplicationLibCode/ProjectDataModelCommands/RimcEclipseCase.h b/ApplicationLibCode/ProjectDataModelCommands/RimcEclipseCase.h
index 4b24f51..bd5c712 100644
--- a/ApplicationLibCode/ProjectDataModelCommands/RimcEclipseCase.h
+++ b/ApplicationLibCode/ProjectDataModelCommands/RimcEclipseCase.h
@@ -31,6 +31,16 @@
 
 class RimCellFilter;
 
+class RimcEclipseCase_gridUnitSystem : public caf::PdmObjectMethod
+{
+    CAF_PDM_HEADER_INIT;
+
+public:
+    RimcEclipseCase_gridUnitSystem( caf::PdmObjectHandle* self );
+    std::expected<caf::PdmObjectHandle*, QString> execute() override;
+    QString classKeywordReturnedType() const override;
+};
+
 //==================================================================================================
 ///
 //==================================================================================================
diff --git a/ApplicationLibCode/UnitTests/RifEclipseInputFileTools-Test.cpp b/ApplicationLibCode/UnitTests/RifEclipseInputFileTools-Test.cpp
index 43e6384..df8cfca 100644
--- a/ApplicationLibCode/UnitTests/RifEclipseInputFileTools-Test.cpp
+++ b/ApplicationLibCode/UnitTests/RifEclipseInputFileTools-Test.cpp
@@ -868,3 +868,37 @@ TEST( RifEclipseInputFileToolsTest, ExportKeywordsInvalidParams )
 
     EXPECT_FALSE( exportSuccess2 ) << "Should fail when passing empty file name";
 }
+
+TEST( RifEclipseInputFileToolsTest, GridUnitControlsLoadedCaseUnits )
+{
+    QTemporaryDir directory;
+    ASSERT_TRUE( directory.isValid() );
+    for ( const auto& unit : { QString( "METRES" ), QString( "FEET" ), QString( "CM" ), QString( "INVALID" ) } )
+    {
+        const auto path = directory.filePath( unit + ".GRDECL" );
+        QFile file( path );
+        ASSERT_TRUE( file.open( QFile::WriteOnly ) );
+        QTextStream stream( &file );
+        stream << "SPECGRID\n1 1 1 1 F /\nGRIDUNIT\n'" << unit << "' /\n"
+               << "COORD\n0 0 1000 0 0 1010\n100 0 1000 100 0 1010\n"
+               << "0 100 1000 0 100 1010\n100 100 1000 100 100 1010 /\n"
+               << "ZCORN\n4*1000 4*1010 /\nACTNUM\n1 /\n";
+        stream.flush();
+        file.close();
+        auto data = std::make_unique<RigEclipseCaseData>( nullptr );
+        QString error;
+        const auto loaded = RifEclipseInputFileTools::openGridFile( path, data.get(), false, &error );
+        if ( unit == "INVALID" )
+        {
+            EXPECT_FALSE( loaded );
+            EXPECT_FALSE( error.isEmpty() );
+            continue;
+        }
+        ASSERT_TRUE( loaded ) << error.toStdString();
+        const auto expected = unit == "FEET" ? RiaDefines::EclipseUnitSystem::UNITS_FIELD
+                              : unit == "CM" ? RiaDefines::EclipseUnitSystem::UNITS_LAB
+                                             : RiaDefines::EclipseUnitSystem::UNITS_METRIC;
+        EXPECT_EQ( expected, data->unitsType() );
+        EXPECT_EQ( 1u, data->mainGrid()->cellCount() );
+    }
+}