Aim. To assess the prehospital diagnosis of unstable angina pectoris (UAP) in the population of a mid-urbanized town in West Siberia. Subjects and methods. The study was conducted using the WHO epidemiological program "The acute myocardial infarction registry" that had been implemented in Tomsk since 1984. All the registered patients aged 20 to 70 years who had been diagnosed as having unstable (progressive) angina pectoris before admission to hospital and after its discharge were examined. Results. A total of 2760 cases of suspected UAP were registered over the 2-year study period. 2139 (77.5%) patients were examined, which allows the findings to be considered to be significant. UAP was verified in 1477 (69.1%) patients. During the follow-up period, 1175 (79.5%) of the examined patients sought medical advice for acute UAP, most did at an emergency care station and regional polyclinics. The detection rate of the disease was 82.4% during the primary examination. In accordance with the diagnosis made, 65.48% of the patients were sent to hospital, including 81.42% who were to the therapy hospitals operating around the clock. 406 subjects were non-hospitalized; of them 313 (77.09%) refused hospitalization; in this connection, they were referred for a cardiology dispensary to receive outpatient treatment. Conclusion. The prehospital diagnosis of UAP was found to have a rather high level while only every five patients with verified UAP were admitted to a specialized hospital.