The survey on outpatients compliance in the treatment of respiratory tract infections was performed in Croatia during April 1996. A total of 213 physicians, 201 adult patients, and 178 parents of sick children were polled by the appropriate questionnaires. The results have shown that in the treatment of respiratory tract infections physicians commonly prescribe thrice-daily antibiotic regimens for 8-10 days. Concerning patients' knowledge, 85% of patients deem that regularity, and 64% that duration of antibiotic administration influences treatment outcome. Over 80% of patients are compliant with once-or twice-daily regimens, but only 50% take regularly and timely drugs that are dosed every 6 or 8 hours. Common reasons for irregular taking of antibiotics are forgetfulness and dosing during sleeping. In terms of appropriate duration of antibiotic therapy, about 20% of patients usually take antibiotic for 8-10 days, 60% for 5-7 days, and 20% for < or = 4 days. It may be concluded that the patients are poorly compliant with oral antibiotics treatment.