This study empirically investigates the extent of both mandatory and voluntary disclosure in the annual reports of banking sector of Pakistan. It also examines the association between total disclosure level (mandatory and voluntary) and firm-specific attributes of the sample banks. The annual reports of 24 commercial banks listed on Pakistan Stock Exchange (PSX) are content analyzed for the year 2015-16. A disclosure index of 219 items was selected, out of which 117 were mandatory and 102 were voluntary items. The results reveal that average total disclosure level is 70%. Average score for mandatory and voluntary items is 100% and 54% respectively. The regression analysis indicates that assets-in-place, age and board composition are significant in explaining the disclosure level. The results reveal that banks in Pakistan are very compliant towards mandatory disclosure, which indicates that regulatory bodies are functioning well and their implementation is strong and effective. Overall, this study is a valuable contribution to the field of disclosure of information in annual reports of banking sector of Pakistan, as in Pakistan very limited work has been done on disclosure of information in annual reports.