A total of 60 healthy pesticide sprayers (smokers and non-smokers) in cotton fields exposed to different classes of pesticides for many years were compared with controls matched for age with respect to serum cholinesterase (ChE), serum total protein, alkaline and acid phosphatases (ALP and AP), lactate dehydrogenase (LDH), gamma-glutamyl transferase (GGT), creatine kinase (CK), blood glucose, serum hormones FSH, testosterone and L-thyroxine (T4). Significant increase was observed in serum ALP, AP, LDH, GGT, CK, serum hormones FSH, testosterone, L-thyroxine and blood glucose. Significant decrease in serum total protein and ChE. The increase or decrease in the tested biomarkers was more pronounced in the smokers than non-smoker workers. These results suggest that the long-term exposure of various pesticides on sprayers of cotton fields affect the normal functioning of different organ systems and may produce characteristic clinical effects.