The author surveyed the population of a state hospital (N = 281) to ascertain the level of knowledge patients had about their medication. Approximately 8% of the patients correctly indicated the name of at least one medication they were taking, its dosage schedule, and its intended effect; approximately 54% of the patients evidenced no understanding of the medication they were regularly taking. Significant differences in understanding of medication were found as a function of diagnosis, age, and length of stay. The finding that few patients were knowledgeable about their medication raises doubts about recent court rulings on patients' competency to refuse medication.