Peru has a low coverage of deaths with a cause of death (54%) and a poor-quality registration of causes of death, as about 30% of causes of death are classified as poorly-defined or not very useful for the formulation of public policies. In response to these problems, the Ministry of Health, together with other government agencies, with the support of the Bloomberg Philanthropies «Data for Health Initiative,» is implementing the National Death Registry Information System (SINADEF). The objective of this article is to describe the process of strengthening the mortality information system in Peru, focused on the implementation of SINADEF. The activities that have been carried out are described in the following areas: a) Management of the mortality information system, b) Process standardization, c) Use of information and communication technology, d) Coverage of deaths with medical certificate, e) Improvement of the quality of information, f) Development of studies, and g) Monitoring of processes. Since the implementation of SINADEF in August 2016 until July 2018, 28,407 users of the SINADEF application have been created and a total of 122,411 deaths have been registered. The quality of data recording, including the cause of death, has been improved, while low coverage of deaths with a cause of death still persists.