Fifty cases of brucellosis attending our Service of Internal Medicine during the period 1985-1990 are restrospectively studies. The number of patients in which the potential transmission mechanism and the risk factor involved are unknown is very high, being the percentage higher among women from urban areas (50%). Thus, greater attention should be paid to transmission sources considered unfrequent and to survival of the germ in several biological environments, as well as to consumption of non-pasteurized dairy products. The evolution period of the disease until hospitalization and diagnosis is large (48.6 days), especially in its oligosymptomatic forms. The diagnostic method is based mainly in clinical observations plus agglutinations, with positive hemocultive as the diagnostic method in just 6% of the cases. Treatment with streptomycin and tetracycline is still highly effective.