Population-based cancer registries (PBCRs) are a key element for cancer control. They measure cancer incidence and trends, provide indicators for planning and evaluating cancer control activities, and undertake research. The first two PBCRs in Spain were established in Zaragoza in 1960 and Navarre in 1970, but it was from 1980 to 1995 when most of the existing registries went into operation. Today, 26.5% of the Spanish population is served by a cancer registry. All registries' quality-control indicators meet the inclusion criteria for comparability and quality of data required by the International Agency for Research on Cancer, and indeed some fulfil most of the excellence criteria for gold standard certification. After their initiation into recording accurate and complete information targeted at ascertaining cancer incidence in their catchment areas, PBCRs are progressively broadening their scope and becoming increasingly involved in collecting and analysing additional data on patient care, diagnosis, disease stage, treatment and follow-up. Spanish registries have become actively engaged in research projects, domestic and international, at a rate that has risen remarkably in the past decade. The creation of a network of Spanish cancer registries is being considered, with the aim of its becoming a key player in developing standards for cancer registration, providing training and technical assistance, undertaking quality audits and promoting the use of cancer surveillance data to reduce the burden of cancer in Spain.