A study was conducted among out-patients attending the Melaka Tengah Health Clinic to determine their compliance status towards antihypertensive, antidiabetic and antiasthmatic drugs. A total of 585 patients were enrolled in this study. Assessment of compliance was carried out using pill-counting and house-to-house interviews 14 days from the date of medication dispensed at the counter. The noncompliance rate among the 464 successfully interviewed patients was 56%. The mean noncompliance percentage was 78.0 +/- 43.1% (range: -10.0-314.3%). Among the four variables of compliance studied, race was not seen as a determinant of compliance. The older age group and those taking two or more drugs were statistically significant to be a noncomplier. Females were highly likely not to comply with drug therapy. Patients who conform to their refill dates were not really drug compliers. Forgetting to take their drugs and inability to read instructions on drug labels were the main reasons given. Underdosing was more common than overdosing, with an estimated cost of RM20,261.00 of unused medications per year.