In this paper the public-private wage gap is estimated by means both of the OLS and the quantile regression, which will provide a more complex picture of the distribution of the public-private sector wage gap. The author finds the existence of significant public-private wage gap (about 30%) considering both observable and unobservable characteristics of workers and jobs. Using the decomposition based on quantile regression helps to answer the question about the nature of the wage differences. The author comes to the conclusion that the main reason for the gap is the institutional mechanisms of public sector wages in Russia. The analysis is based on the data from Russian Longitudinal Monitoring Survey (RLMS-HSE) 2000-2010.