The otter civet Cynogale bennettii is a specialized, semi-aquatic viverrid found throughout the forests of South-east Asia. Although described over 160 years ago, little is known of the species' natural history, and questions remain regarding its taxonomy and distribution. We compiled an exhaustive list of museum specimens and observations to reassess the conservation status, taxonomy and distribution of this species. Data were collected from museums, literature, field surveys, and from other field scientists. Although two species of otter civet have been described, C. bennettii and C. lowei, our morphological examinations do not support specific differentiation. The presence of the otter civet was confirmed for peninsular Thailand, Malaysia and the islands of Sumatra and Borneo. However, more northerly distributions were not confirmed, including the supposed origin of C. lowei from northern Vietnam. Based on the scarcity of recent observations or carcasses, otter civet populations are probably in decline. Recent increases in the number of wildlife surveys throughout the putative range of the otter civet have rarely documented the species. The reduction in primary forest habitat has probably reduced otter civet populations and threatens the persistence of this unique species.