Fish exposure to agrochemicals can suppress their immune system and survival. Therefore, this study investigates adverse effects of sublethal concentrations of Dimethoate alone or combined with Bacilar (an organophosphorus pesticide and bio-fertilizer) on the innate immune parameters of common carp, Cyprinus carpio, within 14 days. No significant changes were found in levels of total protein, immunoglobulin, the activity of lysozyme and complement C3 in fish exposed to Bacilar alone; however, globulin and complement C4 level indicated a significant reduction. Fish exposure to Dimethoate alone or combined with Bacilar resulted in a decrease in the activity of ACH50, lysozyme, complement C3, C4 and levels of total protein, globulin, and immunoglobulin in compared with the control group. In conclusion, the results of this study showed that innate immune parameters decreased in fish exposed to dimethoate and/or Bacilar. As consequences: Dimethoate or/and Bacilar have the immunosuppressive effect on fish.