This research deals with integration processes in the commercial banking market in the Russian Empire at the end of the 1890s. The integration is studied through interest rate analysis: the smaller the difference in interest rates between regions and periods means greater market integration, as well as an easier way for banks to move resources to regions of potential growth. The average annual rate of return on all loans in a bank is used as a substitute for interest rate in this study. This rate has been calculated for any central office or regional branch of the Russian joint-stock commercial banks in 1897, based on the banks’ annual reports. These data on bank units are grouped in accordance with large economic and geographical regions of the Russian Empire. According to the statistical analysis, including regression, lending rates of commercial banks fluctuated within a narrow range of 6—8 % in most regions and higher rates were relatively rare. The regional interest rates’ distribution can be explained by supply-demand effects (the more resources there were in the region the lower rates were there), scale effects (larger banks offered lower rates), as well as effects related to market imperfections when access to bank loans was mainly for groups of privileged customers, close to the bank’s owners and its top-level managers (credit rationing).