OBJECTIVETo analyse the use of drugs to combat infection, prescribed in primary care in the La Rioja area during 1996.DESIGNA retrospective observational study.SETTINGPrimary care.PARTICIPANTSAll the anti-infectious drug prescriptions in primary care during 1996 in our province (450078 units). They are covered by the following therapeutic groups: JO1 (systemic antibiotics), JO3 (systemic chemotherapeutic drugs), JO4A (anti-tubercular), JO5A (antiviral), GO4A (antiseptic and for urinary infections) and RO5C1 (expectorants combining mucolytics and anti-infectious drugs).MEASUREMENTS AND MAIN RESULTSAll the prescriptions for anti-infectious drugs billed in the National Health Service in La Rioja during 1996 were processed. The defined daily dose (DDD) was used as the technical unit of measurement. The DDD per 1000 inhabitants per day (DID) was used as comparative indicator. The DID for the various therapeutic groups was compared with the overall consumption of antibiotics in 1996 in La Rioja.CONCLUSIONSNon-hospital consumption of anti-infectious drugs during 1996 in La Rioja reached 20.97 DID, which is slightly higher than in other areas. The five therapeutic groups with most prescriptions were: penicillin (8.78 DID), macrolides (4.86 DID), cephalosporins (2.48 DID), quinolones (1.25 DID), antiseptic and urinary anti-infectious drugs (1.11 DID). The new macrolides were used a lot, as were quinolones and third-generation cephalosporins. These last two groups are not first-choice drugs in the empirical treatment of pathologies common in primary care.