This study investigates the transformation of competitive dynamics between formal sector retailers and their informal sector counterparts in Eastern European and Central Asian countries after the 2008-2009 global financial crisis. The absence of extensive government bailouts in these regions intensified the economic repercussions of the crisis. This study used data from the BEEPS II and BEEPS IV (i.e. Business Environment and Enterprise Performance Survey) surveys conducted by the European Bank for Reconstruction and Development and the World Bank with a focus on informal competition in Eastern Europe and Central Asia based on data from owners or top-managers of companies working in this region. To investigate the impact of the global crisis on informal competition for retailers, survey results in 2008 (“crisis period”) were compared with the data in 2013 (“post-crisis period”). Non-parametric tests, specifically the Mann-Whitney-Wilcoxon tests, were used to compare the 2008 and 2013 results. Binary logistic regressions were used to identify factors influencing the perception of competition from the informal sector (Pearson correlation coefficients and assessed Variance Inflation Factors to detect multicollinearity issues). Findings reveal a significant shift post-crisis shift with a reduced proportion of formal sector retailers competing with informal firms. Notably, this effect is statistically insignificant for retailers with sole proprietorships and partnerships and those with internationally recognized quality certifications. Moreover, research highlights a diminished perception of informal competitors as substantial hindrances to retailers’ business operations post-crisis. However, this observation is not statistically significant for retail businesses structured as partnerships. Logistic regression indicates that smaller firms, firms led by a more experienced top manager, and firms with a female top manager are more prone to perceive competition from the informal sector. Furthermore, this study delves into the factors shaping retailers’ perceptions across post-Soviet and other transition countries, revealing differences in the impact of firm size and female ownership. This nuanced investigation contributes depth to the current literature concerning the interconnections between formal and informal retail sectors. It offers a comparative analysis focusing on post-Soviet states and other transitioning nations in Eastern Europe and Central Asia.