The objective of this study was to detect and evaluate the use of restricted antibiotics (RAs) in our ambulatory care site. We retrospectively analyzed 1084 treatments of a selected group of intramuscularly administered antibiotics that are usually considered restricted for use in hospitals. Five cephalosporins, four aminoglycosides, and one acylureidopenicillin were analyzed. The study was conducted in 47 primary health centers over six months. We reported the information on a special order from for parenteral prescriptions and evaluated the selection and the dosing interval of each antibiotic. Of the 1084 treatments, cefonicid was the antibiotic most frequently prescribed (61.3 percent), followed by tobramycin (15.3 percent), cefotaxime sodium (6.7 percent), amikacin (3.8 percent), cefuroxime (3.8 percent), mezlocillin (3.7 percent), netilmicin sulfate (3.7 percent), ceftizoxime sodium (0.8 percent), cefoxitin (0.5 percent), and streptomycin sulfate (0.4 percent). Based on our survey criteria, 59 percent of the 710 orders that indicated diagnosis had a correct or possibly correct indication; the remaining percentage was considered unnecessary therapy or poor drug choice. Of the 1050 orders that indicated a dosing interval, 75.4 percent showed an appropriate dosing interval. We assume that most of the infections treated in our ambulatory care site could be resolved with or without common antibiotics. In this study we obtained objective data of the use of ten RAs in order to determine if their use in ambulatory patients was justified. We observed that a small number of prescriptions agreed with the recommened criteria stated in this survey for use of these antibiotics in outpatient infections.