Evaluation of a pharmacy assessment for geriatric patients on a geriatric assessment and rehabilitation unit is described. The assessment has been developed to identify functional, comprehension and therapeutic problems affecting an elderly patient's ability to self-medicate. The pharmacy assessment identified more obstacles to self-medication than the nursing and medical assessments. The detection of obstacles was particularly apparent in the areas of medication knowledge deficit, complicated medication regimes and the inability to follow directions. The pharmacist made more recommendations than the other health professionals for improving the safety and efficacy of drug therapy and medication compliance (p less than .01). Recommendations included simplification of medication regimes, requesting drug levels or specific lab tests, and the use of compliance aids. Seventy-seven percent of the recommendations made by the pharmacist were acted upon by the physician or nurse. Results of the study demonstrate the pharmacy assessment was the most significant predictor of self-medication success.