Primaria (BIFAP) is a population based database administered by the AEMPS (Spanish Agency for Medicines) of longitudinal electronic medical records (EMR) of patients attended in primary care. Its main purpose is to serve as source of information for independent studies on drug safety and support of medicines regulation activities. This article aim is to describe the characteristics of BIFAP, how to access the database and a summary of its potential for research. Methods: Health problems are registered by primary care physicians as episodes of care and include socio-demographic data, results of diagnostic procedures, lifestyle data, general data, and interventions. A proportion of data on hospitalizations and specialist care are currently available through linkage with other data sources. EMRs