Current situation with electoral polls in Ukraine suggests that the ability of the survey industry to obtain accurate information about society requires certain checks and control refinements, and even disclosures. To assess how reliable political sociological ratings are, it is proposed to consider the examples of the last two national election campaigns of 2019 (presidential and parliamentary). The fact-checking method is considered as one of the ways to ensure the reliability of pre-election forecasts. With its help, the reliability of the results of opinion polls and the degree of trust in sociological companies and services (pollsters) are investigated based on the processing of data obtained during the last month before voting day in the national elections in Ukraine. To implement fact-checking, statistical indicators of the average, absolute and relative error were used, and the concept of «negative points» was introduced to assess the results of the opinion poll (sociological company), which are associated with the value of the relative error. The processing and analysis of data from 23 opinion polls of voters during the presidential election campaign and 44 during the early elections to the Ukrainian parliament in 2019 made it possible to obtain tools that, in the future, will ensure the «cleaning» of published results of sociological research from possible manipulations.