This paper analyzes interest margin determinants in the Russian banking sector with a particular emphasis on the bank ownership structure. Using a unique bank-level data covering Russia’s entire banking sector for the 1999−2007 period, we find that the impact of a number of commonly used determinants such as market structure, credit risk, liquidity risk and size of operations differs across state-controlled, domestic-private and foreign-owned banks. At the same time, the influence of operational costs and bank risk aversion is homogeneous across ownership groups. The results overall suggest the form of bank ownership needs to be considered when analyzing interest margin determinants.