We estimate the size of income underreporting in Poland by following and extending the consumption method of Pissarides and Weber (1989). Our study shows that underreporting of income occurs among households with income from self-employment. We do not find any significant underreporting activity by the employees working in the private sector. The main findings indicate that roughly one-fourth of the total income of self-employed households is not reported in Poland. This share varies between 20 to 30 percent from 2005 to 2017 with a decreasing trend.