In parliamentary democracy, opposition has significant role in the parliament. It keeps check on the policies of government and proposes alternative policies against the policies of the government. In the period 2008 to 2018, the two major parties of Pakistan- PPP and PML-N- had ruled the country for five years each. In PPP government (2008-13), PML-N was the major opposition party collaborated by other smaller parties whereas in PML-N government (2013-18), PPP and PTI were the major opposition parties combined with other smaller parties. This research analyzes the role of opposition benches in the governments of PPP and PML-N. Qualitative research method has been adopted for the research. It is an analytical research which evaluate the already available facts and information for finding out the role of opposition in the Parliament of Pakistan from 2008 to 2018. Besides, interviews have also been conducted from different parliamentarians to provide authenticity to the research. In PPP’s government, opposition benches have played a remarkable role not only in the constitutional amendments but also in legislation. It was impossible to pass the constitutional amendments from the parliament without the support of the opposition benches. The opposition parties have made objections on those contents of different legislations which violated the fundamental rights of the people and proposed various alternative policies to the treasury benches. Opposition parties have also historic role in the constitutional amendments adopted in PML-N’s government. The 25th amendment or KP-FATA merger bill was the struggle of the opposition benches. On the other hand, 21st and 23rd amendments which were related to the establishment of military courts and against the ideologies and manifestos of the opposition parties were also passed with the support of the opposition benches. Opposition benches have fervently participated in elections for various slots in the parliament. They nominated their own candidates against the candidates of the treasury benches to prove their existence. The elections in parliament show that unity among the opposition parties have significant impacts on the results of these elections. It is worth mentioning that both the major parties of Pakistan PML-N and PPP had opposed those policies while sitting on the opposition benches which they adopted in their own governments. The opposition benches in the period 2008 to 2018 were a loyal opposition. It neither tried to topple the government nor attempted to change the whole system of the government. It criticized those policies of the government which were against the general interest of the common people of Pakistan. On the other hand, it proposed different alternative policies against the policies of the government.