We report on the natural history of 3 rare and mostly unstudied felids, the clouded leopard (Neofelis nebulosa), Asiatic golden cat (Catopuma temminckii), and marbled cat (Pardofelis marmorata), in Phu Khieo Wildlife Sanctuary, Thailand. From February 1999 to February 2003, 4 clouded leopards (2 males and 2 females), 2 Asiatic golden cats (1 male and 1 female), and 1 female marbled cat were captured, radiocollared, and tracked for 1–17 months. Clouded leopards exhibited annual ranges (95% minimum convex polygon) of 22.9–45.1 km², traveled an average of 1,932 m each day, and were active during 58% of diel activity readings. Asiatic golden cats ranged 32.6–47.7 km², traveled an average of 1,597 m each day, and exhibited an arrhythmic activity pattern of 58% activity. A marbled cat was tracked for 1 month, ranged 5.3 km², and was primarily nocturnal in its habits. Examination of limited data indicated diverse prey use by clouded leopards. Illegal hunting and collecting of aloewood (Aquilaria crassna) threaten the felid community in Phu Khieo Wildlife Sanctuary.