Serum kinetics of bothropic venom were evaluated in eight snakebite patients, who due to a national shortage, received no specific antivenom therapy. The cases were clinically classified as mild, moderate, and severe. Patients were bled sequentially and serum levels of venom were assayed by ELISA. Venom level ranges differed among the groups, with peak levels of less than 13 ng/ml, 32 ng/ml, and 120 ng/ml for the mild, moderate, and severe groups, respectively. There was no clear pattern of kinetics in the groups. Regression analysis involving the variables severity and peak venom levels yielded a statistically significant correlation (rs = 0.80, P less than 0.05). These data indicate that different amounts of circulating venom correlate with clinical severity, even in highly complex venoms, and stress the importance of careful clinical classification in the proper management of bothropic incidents.