The first microcensus in the Soviet Union was held in January 1985, when 5% of the country's population were counted. A microcensus differs from a pilot census by the number of respondents and by its geography, since the former is carried out nationwide.

The 1985 microcensus was based on lists of voters: 5% of polling stations in all regions of the country were covered.

The main counting unit was the family, rather than (as nowadays) the household. This choice was motivated, among other reasons, by the goal of assessing the impact of a new demographic policy that had begun to be implemented in the early 1980s.

Overall, the census programme included 27 questions: general details about the respondent, information about marriage and children, living conditions, and the person's opinion of current demographic policy. For the first time, women aged under 45 were asked how many children they expected to have.