© 2018, ALÖKI Kft., Budapest, Hungary. Glyphosate is the most used herbicide in the world. In 2015, it was declared as probably carcinogenic to humans by the International Agency for Research on Cancer. In Valle del Mayo, Sonora, México, more than 20000 L of this herbicide are sprayed per year. Therefore, the objective of this work was to assess human health risk associated with exposure of water contaminated with glyphosate and aminomethylphosphonic acid (AMPA) on a population in agricultural fields of Valle del Mayo communities. A cohort study was performed among the exposed populations; glyphosate and AMPA concentrations were measured in water drains, private wells, and groundwater by high-performance liquid chromatography (HPLC). Health risk was subsequently assessed obtaining a hazard ratio. Concentrations for glyphosate were lower than 5 µg L-1 while those for AMPA were 15-342.5 µg L-1 or µg g-1. The results showed a statistical correlation among people consuming water from private wells with diabetes (p ≤ 0.03) and hypertension (p ≤ 0.004). The resulting risk assessment hazard ratio was 0.22 for agricultural laborers and 0.39 for brick makers when an acceptable daily dose of 0.03 mg kg-1 d-1 was taken into account, indicating a potential health risk.