In order to evaluate the prescription practices on gentamicin, we screened retrospectively the case records of 600 patients admitted to this hospital. Of these, 100 received gentamicin, in combination with other antibiotics, as the initial treatment. Therapy with gentamicin was considered to be indicated in 71 cases; 62% were below 1 year. Patients with neonatal septicemia, meningitis, serious staphylococcal infections and those who were immunocompromised received appropriate treatment with the drug. All the bacteria cultured were sensitive to the antibiotic. Gentamicin was unnecessarily prescribed to 29 cases including bronchial asthma (n = 7), bronchiolitis (n = 6) and acute gastroenteritis with dehydration (n = 8). In most of the latter cases, the use of gentamicin indicated the psychologic dependence, of the physician, on the drug. Nine patients showed gentamicin-related nephrotoxicity. Formulation of standard treatment guidelines and regular medical audits are necessary to improve quality of prescribing and avoid misuse of drugs.