In the population and housing census which was carried out in Poland in 2011 a new organizational and methodological approach was applied. Poland was among those countries who decided to abandon the traditional method and to apply a mixed method. This document presents selected aspects of census methodology as well as a scope and method of collecting data on international migration in the census. Broad range of international migration survey was determined both by national data requirements and the need of compliance with international obligations laid down in the relevant legal acts. It was also crucial to obtain in 2011 census information on the issues covered by the census in 2002. The magnitude of data sources used in the Polish 2011 Census provided many data collection opportunities, but, at the same time, caused problems that had to be solved in order to combine data from different sources in an appropriate way. The presented material includes a description of the solutions, together with their strengths and limitations.