In seeking broad spectrum pharmacological activitie s of 2-mercaptobenzimidazole moiety, a series of 2-mercaptobenzimidazole derivatives were synthesized by mannich reaction and screened for analgesic activity by hot plate method and tail flick method. Totally a series of ten new 2-mercaptobenzimidazole derivatives (1A-1J) wer e synthesized from 2- mercaptobenzimidazole by reaction with compounds ha ving secondary amine and formaldehyde. The purity of the synthesized compounds was checked by melting point and TLC and their structure was established by various analytical tec hniques such as IR and 1 HNMR spectral studies. All the synthesized compounds were exhibit ed significant analgesic activity when compared with standard drug, pentazocine.