A study was designed aimed to know rates of influenza vaccine prescriptions among medical staff personnel and postgraduate medical student in a tertiary care teaching hospital. Data was collected by a questionnaire asking for previous year prescription, age of patients seen at the outpatient clinic, years of professional experience and other potential factors that may influence its use. A total of 103 physicians were consulted, including 14.8% of 452 staff physicians and 16.3% of 220 postgraduate medical students. Forty percent of the requested doctors indicated influenza vaccine during 1999. This rate was quite similar among doctors that work seeing older persons at outpatient clinics (43.5%). Rates were similar among staff doctors and postgraduate medical students. Prescription of the vaccine was more frequently declared among physicians working at the Internal Medicine Department although differences with other services were not significant. Thirty percent of the vaccine indications were temporarily inadequate and used after the reasonable time-frame before the influenza season. Influenza vaccine is an underprescribed preventive strategy