A very hot debate at the popular level has been going on in Nepal about the executive system as the popular perception is that the parliamentary system is behind the widespread power abuse and corruption, including institutional ones, and the lack of development of the country. Many advocates argue for the establishment of a presidential system, without adequate knowledge about it, even though the topic has been widely researched by academics around the world, and there is almost a consensus among scholars about the “perils of presidential systems” (see Linz 1990 and 1990, Linz and Valenzuela 1994, Stepan and Skach 1993, Mainwaring 1993, Riggs 1997, Valenzuela 2004, Kim and Bahry 2008). The lack of presidential systems in the neighborhood may have deprived knowledge about it in Nepal at the popular level. The public debate in Nepal has largely been about parliamentary versus presidential systems whereas, in fact, four types of executive systems exist (Presidential, Semi-Presidential, Westminster/winner-take-all Parliamentary and Vibrant/Western European Parliamentary systems), and there are clear differences between the variants of presidential and parliamentary system themselves. A lack of systematic academic investigation on the subject has not been carried out yet in Nepal, and this may have also contributed to the public misperceptions. This study aims to do that taking into account the Nepali context and Nepali political culture, especially power concentrating culture of the political elite, street movements over even minor issues, and widespread patron-client relationship in the political parties. This study will compare empirically the Westminster (1990-2002) and non-Westminster parliamentary (since 2015) systems in Nepal with Presidential and Semi-presidential systems with secondary global data on along the parameters of stability, delivery/governance performance, corruption control, and inclusion, four issues that are often presented to argue for major institutional reform. Three parliaments under the Westminster and two parliaments under non-Westminster systems have been elected in Nepal, making the two parliamentary systems empirically comparable. Hung parliaments were elected under both parliamentary systems – the Westminster system witnessed frequent government changes in hung parliament while only one government change took place under non-Westminster system, demonstrating improved changes. Likewise, more corruption issues have been raised under the non-Westminster parliamentary system in Nepal. The study will cite literature from around the world to demonstrate that all presidential systems have gone through at least one major crisis while parliamentary systems have not. The frequent impeachments, forced resignations, frequent changes in presidents, destructive street movements, military coups under the presidential systems will be presented. The study will argue that not only was the Westminster system been problematic in Nepal, including in non-homogenous societies around the world, the presidential system has been problematic all around the world and that it may become even more problematic based on elite Nepali political culture. Based on empirical data and available literature, the study will argue that reform of the parliamentary system to make it more vibrant will make the Nepali polity more stable, accountable, effective and inclusive.