This thesis researches the effect of liberalization on postal sector employment and working conditions between 1990 and 2010 in ten EU member states. Three indicators have been used to determine the extent of liberalization, namely entry regulation, the presence of postal competitors and state ownership. Moreover, two control variables have been introduced in order to avoid automatically associating any difference to liberalization. This research has shown that all assessed variables cannot explain the developments in employment and working conditions in the postal sector. Indeed, also countries without liberalization present in the postal sector showed increased precariousness in employment and working conditions. Also correlation between the control variables and postal sector employment and working conditions could not be proven. Based on the results and arguments presented in this research, it is likely that liberalization has not had a significant effect on employment and working conditions in the postal sector.