A captive woolly monkey (Lagothrix lagothricha) displayed severe lethargy, vomiting and diarrhea. Laboratory tests revealed anemia, leukopenia, hypoproteinemia, severe azotemia and positive Leptospira IgM ELISA. The monkey was humanely euthanized and the necropsy revealed a multifocal tubulointerstitial glomerulonephritis; in addition to splenic lymphoid depletion, and interstitial pneumonia, all of which are compatible with leptospirosis. Rodent control and biosecurity measures should be done at all zoological collections in order to prevent transmission to facility personnel and to threatened mammals maintained in captivity.Key words: Epidemiology, leptospira, primate, zoo (Source: DeCS).