Tramadol hydrochloride is a mild, non-addictive, centrally acting binary analgesic agent, during the process development of Tramadol hydrochloride, four related substances (Impurities) were observed along with the final API.Those impurities were identified as,[2-(3-methoxyphenyl) cyclohex-1-enyl]-N,N-dimethylmethanamine hydrochloride(6),(1RS)-[2-(3-methoxyphenyl)cyclohex-2-enyl]-N,N-dimethylmethanaminehydrochloride(7),(3- ((1R,2R)-2-((dimethylamino)methyl)-1-hydroxyclohexyl)phenol hydrochloride(9) and 3,3'-Dimethoxy-biphenyl(11). Present work describes the synthesis and characterization of all these four impurities.