The article presents the changes in the level and distribution of seasonal fluctuations in the prices of potato in Poland in the years 1995-2014. It was found a strong decline of seasonal price fluctuations, resulting primarily from the flattening of seasonal price increases during the summer, and the disappearance of seasonal price declines in the spring. In addition to the structural determinants represented in the model by the time variable changes in price seasonality was affected by interest rates.