Six years of necropsy records from a zoo colony of four tamarin species (Saguinus oedipus, S. geoffroyi, S. imperator, and S. mystax) were examined. Mean age at death was 4.0 years, average length in the colony at time of death was 3.4 years. Annual mortality rate varied between 9 and 30%. Gross necropsy findings, histopathologic, and bacteriological results indicate primary cause of death as follows: peritonitis (26%), septicemia (14%), nephritis (5%), hepatitis (5%), pneumonia (2%), and others.