From Westminster-style parliamentarianism to semi-presidentialism, Sri Lanka has experimented with different structures of constitutional governance in the post-independence era. However, the Sri Lankan parliament became a peripheral player within the constitutional structure with semi-presidentialism introduced by the 1978 Constitution. While the Nineteenth Amendment to the Constitution attempted to establish multiple constitutional centres of accountability, the position of the parliament remained peripheral. The centrality of parliament within the constitutional structure is a crucial condition for a robust model of parliamentarianism with effective checks and balances. Based on the example of German constrained parliamentarianism, I argue for the importance of further reform towards transforming the parliament from a peripheral player to the central player in the constitutional structure. Reforms should aim to regulate the composition of the parliament by constitutionalizing parties, to strengthen the institutional capacities of the parliament and to constitutionally assert the autonomy of the parliament vis-à-vis the president.