diff --git a/src/app/code/community/AvS/FastSimpleImport/Helper/Data.php b/src/app/code/community/AvS/FastSimpleImport/Helper/Data.php
index 159b3c96..3070fa79 100644
--- a/src/app/code/community/AvS/FastSimpleImport/Helper/Data.php
+++ b/src/app/code/community/AvS/FastSimpleImport/Helper/Data.php
@@ -10,4 +10,23 @@
  */
 
 class AvS_FastSimpleImport_Helper_Data extends Mage_Core_Helper_Abstract
-{}
+{
+
+    /**
+     * Returns str with all alphabetic characters converted to lowercase.
+     * Uses the multibyte function variants if available.
+     *
+     * @param $str the string being lowercased
+     *
+     * @return string str with all alphabetic characters converted to lowercase
+     */
+    public function strtolower($str)
+    {
+        if (function_exists('mb_strtolower') && function_exists('mb_detect_encoding')) {
+            return mb_strtolower($str, mb_detect_encoding($str));
+        }
+
+        return strtolower($str);
+    }
+
+}
diff --git a/src/app/code/community/AvS/FastSimpleImport/Model/Import/Entity/Product.php b/src/app/code/community/AvS/FastSimpleImport/Model/Import/Entity/Product.php
index dd3aa133..3c58610c 100644
--- a/src/app/code/community/AvS/FastSimpleImport/Model/Import/Entity/Product.php
+++ b/src/app/code/community/AvS/FastSimpleImport/Model/Import/Entity/Product.php
@@ -285,7 +285,9 @@ protected function _createDropdownAttributeOptions()
 
                 $options = $this->_getAttributeOptions($attribute);
 
-                if (!in_array(trim($rowData[$attributeCode]), $options, true)) {
+                /** @var AvS_FastSimpleImport_Helper_Data $helper */
+                $helper = Mage::helper('fastsimpleimport');
+                if (!in_array($helper->strtolower(trim($rowData[$attributeCode])), $options, true)) {
                     $this->_createAttributeOption($attribute, trim($rowData[$attributeCode]));
                 }
             }
@@ -318,7 +320,9 @@ protected function _createMultiselectAttributeOptions()
 
                 $options = $this->_getAttributeOptions($attribute);
 
-                if (!in_array(trim($rowData[$attributeCode]), $options, true)) {
+                /** @var AvS_FastSimpleImport_Helper_Data $helper */
+                $helper = Mage::helper('fastsimpleimport');
+                if (!in_array($helper->strtolower(trim($rowData[$attributeCode])), $options, true)) {
                     $this->_createAttributeOption($attribute, trim($rowData[$attributeCode]));
                 }
             }
@@ -346,7 +350,8 @@ protected function _getAttributeOptions($attribute)
 
             $this->_attributeOptions[$attribute->getAttributeCode()] = array();
             foreach ($attributeOptions->getAllOptions(false) as $option) {
-                $this->_attributeOptions[$attribute->getAttributeCode()][$option['value']] = $option['label'];
+                $label = Mage::helper('fastsimpleimport')->strtolower($option['label']);
+                $this->_attributeOptions[$attribute->getAttributeCode()][$option['value']] = $label;
             }
         }