A novel series of N-Mannich bases of benzimidazole derivatives were synthesized and characterized by 1H NMR, IR spectral studies and elemental analysis. The compounds were screened for analgesic and anti-inflammatory activity. 1-((Diethylamino)-methyl)-2-styryl benzimidazole 4 at 40mg/kg was found to be equipotent to paracetamol. 1-((Piperidin-1-yl) methyl)-2-styryl-benzimidazole 6 at 40mg/kg was found to be more potent than Diclofenac. ...