The government plays first fiddle in European Union (EU) decision-making processes, but a role in EU governance is also performed by the national parliament, which has gained additional competence to submit reasoned opinions based on the subsidiarity principle and participate in the political dialogue with the European Commission. The authors trace the policy-shaping and policy-taking processes and explore the impact of parliamentary and government involvement in EU policy-making on belated and timely transposition of EU directives in the Czech Republic. This comparative analysis of six directives, of which three were transposed on time and the other three from the same policy areas not, shows that the connection between ex-ante and ex-post stages still seems weak, and thus, greater involvement by parliament in EU affairs does not alone affect the time of transposition. Instead, the capacity of the government, determined partly by the salience of the legislation and its characteristics, is the main explanation for the transposition delays.