The MONICA (Multinational MONItoring of trends and determinants in CArdiovascular disease) Project was established in the early 1980s in many Centres around the world to monitor trends in cardiovascular diseases, and to relate these to risk factor changes in the population over a ten year period. It was set up to explain the diverse trends in cardiovascular disease mortality which were observed from the 1970s onwards. There were total of 32 MONICA Collaborating Centres in 21 countries. The total population age 25-64 years monitored was ten million men and women. The ten year data collection was completed in the late 1990s, and the main results were published in the following years. The data are still being used for analysis.