Using ATC/DDD methodology, we analyzed antibiotic utilization in the Clinical Centre of Banja Luka, one of the largest clinical centres in Bosnia and Herzegovina, during the war and postwar period (1994-2000), as well as the role of drug donations on doctors' prescribing decisions. The retrospective analysis of antibiotic utilization (group J according to the Anatomical Therapeutical Chemical - ATC classification) was based upon the data provided from the hospital computer centre and calculated as the number of defined daily doses (DDD) per 100 bed days. The pharmacoepidemiological analysis showed that the total use of antibiotics changed markedly; in the war year of 1994, as well as in 1998, antibiotics were the second most frequently used group of drugs (19.7% and 14.1% of total drug utilization respectively), while in the following years antibiotics were considerably less used. These dynamics were significantly influenced by drug donations, the percentage of which in the overall antibiotic supply in 1996 was 91.5%, while in 1999 and in 2000 it decreased considerably to 46.8% and 45.6%, respectively. The most widely prescribed antibiotics were penicillins, aminoglycosides, sulphonamides and tetracyclines. Among these, the aminopenicillins, co-trimoxazole, gentamicin and tetracyclines were mainly (70-100%) supplied as a drug donations. However, macrolides, cephalosporins and quinolones were less used due to fact that they were considerably less often delivered through drug donations. It can be concluded that the drug donations had a significant impact on prescribing practice and the rational use of antibiotics in the Clinical Centre studied.