Economic constraints experienced by many African countries make it vital that reliable information is collected about the cost of patient care in health institutions. Case files and treatment charts of 509 patients admitted to non-fee paying medical wards of Queen Elizabeth Central Hospital, Blantyre, Malawi for the month of September 1992 were analysed in order to determine the amount and costs of drugs and antimicrobial agents given to inpatients. Infectious diseases accounted for 76% of all admissions. A total of 59 different drug items were used (cost U.S. $732). In all, 18 antimicrobial agents were given (31% of all drug items) at a cost of U.S. $615 (84% of all drug costs). Calculated costs of antimicrobial agents for each patient and for annual admissions (10325 in 1992) were U.S. $1.21 and U.S. $12,558 respectively. Although the present study has its limitations, it provides a rational basis for planning departmental drug budgets.