Species of the bark louse genus Trichadenotecnum Enderlein (Insecta: Psocodea) from Peninsular Malaysia and Singapore are revised with illustrations and identification keys. Twenty species are here recognised, with four new species and ten recorded for the first time from this region, together with an unnamed species represented by a single female. The previously described species T. marginatum New & Thornton is not included because its generic assignment is questionable. Females of T. cinnamonum Endang & New, T. imrum New & Thornton and T. sibolangitense Endang, Thornton & New, and the male of T. kerinciense Endang & New are described for the first time. A new species group is defined for T. krucilense Endang, Thornton & New.