Background: Eastern European countries adapted differently to the social, political and economic changes after the collapse of the Soviet Union in 1991.With many countries now members of NATO and the EU, the transition experienced by the majority of the post-socialist countries has been considered to be a success story of history.However, these changes also caused pain, bitterness and disappointment for so many people and contributed to a number of social diseases such as alcoholism, tuberculosis, HIV and suicides.The present study aims to test if the factors related to social integration and social regulation are able to explain the changes in the social suicide rate in Eastern Block countries during the transition period.Considering the rise in undetermined death mortality in republics of the former USSR, an analysis of suicide rates together with the mortality of undetermined deaths will also included.Methods: This study used a cross-sectional time-series design and applied panel data fixed-effects regression technique.The sample included thirteen countries of the former Soviet Union and Soviet Block in Eastern Europe able to provide reliable and consistent data to the WHO between 1990 and 2008 (Belarus, Bulgaria, Croatia, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Moldova, Romania, the Slovak Republic, Slovenia, and Ukraine).Dependent variables were gender-specific age-adjusted suicide rates and suicide rates plus undetermined deaths.Independent variables included unemployment, GDP, the Gini index, divorce, birth rate, female labour force participation, alcohol consumption, and GPs per 100,000.Results: Male suicide rates and male suicide/undetermined death rates were positively associated with unemployment, while GDP, GPs per 100,000 and birth rates were negatively associated with mortality rates.However, divorce was positively associated with the suicide/undetermined death rate, but had no effect on the suicide rate.Income inequality was positively associated with suicide and suicide/undetermined death rates for females.Unemployment was positively and GDP per capita negatively associated with female suicide.However, these variables did not have an effect on the undetermined/suicide rate.Female suicide/undetermined mortality had a positive association with divorce, while suicide mortality had a negative association with birth rates.Conclusion: Male suicide and suicide including undetermined mortality rates had similar predictors, which might indicate to the homogeneity in those two groups of mortality and possibility of misclassification of suicides.Both were associated with GDP, unemployment and birth rates.This may indicate that changes in suicide mortality were related socioeconomic disruption experienced during the transition period in Eastern Europe.Surprisingly, male suicide rates in Eastern European countries did not show association with alcohol consumption during the study period.Even so, we have to be cautious when interpreting this result, as there might be underestimation of alcohol consumption due to illegal alcohol and differences in the methodology of calculating alcohol consumption.However, predictors of female suicide and suicide/undetermined death rates showed remarkable differences, which show less homogeneity between two groups for females.