The objective of this paper was to determine the impact of weather conditions on the content of nitrates(V) in potato tubers. The experimental material consisted of seventeen cultivars of potato. The experiment was carried out in the years from 2003 to 2006. The content of nitrates(V) in potato tubers was determined after gathering the potatoes. It was found that the weather conditions as existing in the following periods: 1st week or so of July, mid-July, and 1st week or so of September, essentially impacted the content of nitrates(V) in the potato tubers. The very early cropping cultivars (Karatop and Velox) and the early cropping Gracja cultivar cumulated the highest amounts of those compounds.