That functionality is not implemented in IE. MSDN on Disabled property for option and optgroup: "The disabled attribute can be set and retrieved. However, the functionality specified by the HTML 4.0 standard is not implemented for this property." I suggest that you replace the value for the disabled options with a specific value, for instance -1. Use javascript to check for the value, and also check the value when the form is posted to the server in case Javascript was disabled. --- b { font-weight: normal; }