The prevalence and risk factors associated with leptospirosis were studied in veterinary students in Zaragoza. Sera were collected at the beginning and end of the academic year 1994 to 1995 and were tested by ELISA against a pool of Leptospira intefrogans serovars bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae and pomona antigens. At the beginning of the study the prevalence was 8.14 per cent and at the end it was 11.4 per cent The incidence of the disease during the study was 0.0394. Risk factors associated with leptospirosis included: taking the course specialising in food inspection and technology, on-farm work, contact with pets in general, and particularly carnivores, and contact with animal traders. The symptoms associated with the disease were myalgia and fever, and the treatment of the symptoms provided some protection.