The literature contains no reliable field information for Dermacentor (Indocentor) atrosignatus . Herein, data are recorded for 3530 adult D. (I.) atrosignatus from forests of the Malay Peninsula, Indonesia (Sumatra and Java), Borneo (Sarawak and Kalimantan), and southern Philippines (Palawan and Busuanga). The chief hosts of adults are wild pigs, Sus scrofa sspp. and Sus barbatus sspp. Occasional records, all from the Malay Peninsula, are from the Malayan Sun Bear, Helarctos malayanus ; Malayan Pangolin, Manis javanica ; domestic pig, buffalo, and dog; and 2 reptile species, the monitor lizard Varanus salvator and the Indian Cobra, Naja naja . Adults of 2 or 3 D. (Indocentor) species ( atrosignatus, auratus, compactus , and others to be reported) often occur on the same Sus host, together with Amblyomma testudinarium and several Haemaphysalis species. In the Malay Peninsula tick survey, 3780 D. (I.) compactus were taken from 333 Sus in 51 localities, 1339 D. (I.) auratus from 269 Sus in 35 localities, and 1082 D. (I.) atrosignatus from 245 Sus in 56 localities. Specimens taken from Malay Peninsula forest vegetation where Sus feed were 6752 D. (I.) compactus , 2390 D. (I.) atrosignatus , and 240 D. (I.) auratus . The role of D. (I.) atrosignatus as a reservoir and vector of agents of zoonotic infections, some of which may be transmitted to man by coparasitizing tick species, should be investigated.