Experts use their domain expertise and knowledge of examinees' ability levels as they write test items. The expert test writer can then estimate the difficulty of the test items subjectively. However, an objective method for assigning difficulty to a test item would capture the cognitive demands imposed on the examinee as well as be assignable by any domain expert familiar with the examinee group. One such instrument for assigning objective complexity of general chemistry exam items has already been reported. A revised instrument for assigning objective complexity of organic chemistry exam items is presented including the reliability and validity studies of the rubric.