Objective: To evaluate a training programme in the primary care of acute coronary syndrome. Design: A before-during-after comparative cross-sectional study. Setting: Health areas of Lleida, High Pyrenees and Aran (Spain), from 2003—2006. Participants: Patients with acute coronary syndrome admitted to the intensive medicine unit and the coronary unit of the Arnau de Vilanova University Hospital of Lleida after being referred from home, general practitioner or health centre. Intervention: A training program was introduced to establish protocols of pre-hospital performance in acute coronary syndrome (the administration of acetylsalicylic acid, nitroglycerin and morphine chloride, the performing of an electrocardiogram, the insertion of an intravenous tube and to speed up care times). Main measures: Linear trend of the three periods of the study was analyzed through prevalences ratio and linear trend test. Results: The intervention showed a statistically significant linear increase in the application of the aforementioned therapeutic procedures, with the exception of nitroglycerin, which started out with a higher baseline level, and an improvement of care times. The application of an electrocardiogram obtained almost optimal levels. Care times considerably improved. Conclusions: Training programs are a useful tool in improving treatment of acute coronary syndromes in primary care. Advance diagnosis and an early start to treatment almost certainly results in a decrease of its morbidity-mortality.