The Irrigation District 005 is an agricultural territory in Chihuahua, Mexico where has been detected As in groundwater. So, the objective was to determine As in agricultural wells, and the metalloid traceability to soil and crops. 119 irrigation wells were sampled, 140 samples of soil, 32 onion and 37 chili plants were collected. The As concentration was determined in all matrices by HG-AAS. 11% of the wells exceeded the maximum permissible level (MPL) in Mexico of As in water for agricultural use (100 μg L−1), the highest concentration was 576 μg L−1. 13% of the soil samples exceeded the MPL for agricultural use (22 mg kg−1), the maximum concentration was 57.7mg kg−1. The highest As presence in crops was in root, 7.4 mg kg−1 in chili and 28.8mg kg−1 in onion. However, 0.16 mg kg−1 in chili crop and 0.38 mg kg−1 in onion crop were also identified.