This paper examines and compares the relationships between capital regulations, risk and efficiency of Islamic banks with conventional banks in Pakistan from 2003 to 2015. By employing seemingly unrelated regression (SUR) this study finds that capital regulations have no significant effect on the risks taken by Pakistani Islamic banks. Capital regulations have increased the operational efficiency, while it has neither decreased nor increased the cost efficiency of the banks. The results of this study find no major difference in the capital regulations, risk and efficiency relationships between Islamic and conventional banks. The findings of this study also highlight the significant difference in the effect of capital regulations on the bank risks before and after the Global Financial Crisis of 2008, while there is no difference in the impact of capital regulations on bank efficiency before and after the 2008 crisis.