The sugar market in the EU is among the most regulated food markets in the world. This regulation is based on production quotas and foreign trade regulations. At the same time, individual links of the marketing chain are characterised by highly varied degree of concentration, which – in the conditionsof strong market protection – creates the potential for monopolistic practices and the so-called monopolistic margins. In this context, the paper aims at empirical assessment of changes in sugar prices in Poland and identification of their determinants. The study was based on monthly sugar prices in Poland, the EU and across the world in 2000-2014. Time series models were used to assess correctness. The conducted research indicates that sugar production and prices in Poland and in the EU are largely determined by the market regulation system, while the sugar market reform had little effect on increasing the interrelations between the EU prices and world prices. At the same time, the retail and selling prices are strongly interrelated and these interrelations can be non-linear.