Background: Farmers and their workers are exposed to a wide variety of pesticides. The use of pesticides has been documented to lead to several adverse health effects. Inhibition of cholinesterase, primarily butyrylcholinesterase is a good indicator of occupational exposure to organophosphates and carbamates.Objective: This case-control study aims to study the risks associated with pesticide exposure among farmers and agricultural workers in the Souss Massa region by analyzing variations in the response of a pesticides exposure biomarker: Serum Cholinesterase Activity (butyrylcholinesterase (BChE)).Materials and methods: This was a prospective study conducted on 133 participants (71 farmers and 62 non-farmers). A structured questionnaire was applied collecting socio-demographic information and determining knowledge and work practices in relation to pesticide use. The activity of Serum cholinesterase was measured by the butyrulthiocholine method a spectrophotometric assay.Results: The mean age of the participants was 42.5 ± 10.66 years. The study demonstrated significantly lower BChE activity, respectively, in the plasma of farmers exposed to pesticides, compared to the control group (p < 0.05). The measured mean level of BChE activity was (7304.80 ± 1939.99 U/L) and (9746.42 ± 1699.85 U/L) in the farmers and the control group (non-farmers), respectively. In addition, a high proportion of farmers reported that empty containers are burned in the open (74.6%) for waste disposal. A proportion (11.3%) of farmers also reported that empty container waste is spilled on the farm.Conclusions: The decrease in BChE indicates a serious public health problem among farmers who use organophosphate pesticides. This study suggests that regular monitoring for blood cholinesterase and effective interventions to reduce pesticide exposure to prevent health effects should be provided to farmers.