Nitrate content in agricultural crops is of interest to governments and the general public owing to the possible implications for health. There are two pathways for nitrate to enter into human body: food and drinking water. The dietary intake of nitrate is usually much larger than that from drinking water. This work investigated nitrate content in various crops and its relevance to the nitrate concentration of irrigation water in an arid region, Northwest China. It revealed that irrigation water with high concentration of nitrate tends to produce crops with high build-up of nitrate. Nevertheless, all sampled crops adjust their nitrate distributions in a way that the edible parts contain much less nitrate except lettuce. The nitrate content in the edible root of lettuce reached up to 5900 mg/kg exceeding the limit set by the European Commission. The findings, although preliminary, supplemented the existing literature and raised questions for further study.