Repeated exposure to pesticides can cause a variety of human health problems, particularly among farmers. This work consisted in studying biochemical parameters and their evolution in cotton farmers exposed to pesticides. A longitudinal study was conducted during and after the 2018/2019 cotton season on a cohort of cotton farmers around the Bala hippopotamus pond in the department of Satiri. Biochemical parameters were measured during and after the crop year on the Architect ci 4100. The majority of the farmers had high uric acid (UA) and low blood sugar (Gluc) concentrations. A few had concentrations of Cholinesterase (ChE) (6.19%); Direct Bilirubin (BilD) (23.01%); Gamma Glutamyl Transferase (GGT) (8.85%); Alkaline Phosphatase (ALkP) (4.42%); Cholesterol (Chol) (4.42%); triglycerides (Trig) (4.42%); aspartate aminotransferase (AST) (4.42%) higher than normal and lower than normal albumin (Alb) (13.27%) and total protein (TP) (13.27%) concentrations. Analysis of the evolution of biochemical parameters showed that none of the producers had higher than normal ChE and TP concentrations. After the campaign, the number of producers with lower than normal values increased for AST, AlkP, Alb and Urea while those with higher than normal values increased for GGT, UA, Gluc, Chol, Trig and BilD. Also, a significant decrease in AST, ALT and creatinine (CreaC) concentrations and a significant increase in GGT and BilD concentrations were observed. The existence of some disturbances of biochemical parameters in farmers should encourage to test the hypothesis of a link between pesticide exposure and the appearance of biochemical disorders in clinical trials.