Preferential trade agreements are an important feature of the global trade system. Several questions, ranging from the rationale for preferential arrangements to their impact on members, non-members and the broader multilateral trade system, are at the forefront of academic and policy debates in trade policy. This paper presents a new database that offers a detailed assessment of the content of preferential arrangements, examining the coverage and legal enforceability of provisions regulating a large set of policy areas. The database provides information on 279 agreements signed by 189 countries between 1958 and 2015. The analysis of the data confirms one of the key insights in the literature: preferential trade agreements are becoming deeper over time. A growing number of these treaties regulate an extended set of policies, frequently with legally enforceable provisions, in areas under the current World Trade Organization mandate and in areas outside the current World Trade Organization mandate, especially competition policy, investment, movements of capital, and intellectual property rights protection. Accounting for the changing scope of preferential trade agreements is essential to gain a more complete and accurate understanding of where the global trading system is going and how its governance can be improved.