Existing literature on political dynasties argues that dynastic candidates enjoy a disproportionate electoral advantage. Theoretically, the presence of political dynasties can be considered as a non-institutional barrier to candidacy in the election. Using constituency-level data on national assembly elections (2002, 2008, & 2013) in Pakistan, we study the impact of political dynasties on various metrics of electoral competition. The empirical results show that political dynasties negatively affect political competition in Pakistan. A one-standard-deviation increase in the proportion of dynastic candidates decreases political competition by 13% in a constituency. Similarly, other metrics of political competition also respond negatively to dynastic presence. Furthermore, we also exploit historical colonial rule variations across regions as an instrument to explore the causal effect of political dynasties on political concentration. The instrumental variable (IV) estimates are also consistent with the baseline results.