This study determines how economic, political, and socio-demographic factors impact the parliamentary election outcomes in central and eastern European countries in transition period. A one-way fixed-effect method has been applied to analyze two main economic models. The dependent variables are share of the Western-oriented and traditional-oriented parties. Data of sixteen countries have been used in the thesis. According to the results of this study, it is possible to conclude that outcomes of parliamentary elections in central and eastern European countries depended on political and socio-demographic factors from I 990-2001. Factors such as loans, received from the United States, per capita in the pre-election year, as a measure of external pressure, and share of agriculture in GDP, as a measure of country`s level of development, demonstrate consistent significance in both variations of the model.