Context: Stable angina pectoris in women has often been considered a “soft”d iagnosis, with less-severe prognostic implications than in men, but large-scal e population studies are lacking. Objective: To determine sex differences in the incidence and prognosis of stable angina in a large ambulatory population. Desi gn: Prospective cohort study using linked national registers. Setting: All munic ipal primary health care centers, hospital outpatient clinics, occupational heal th care services, and the private sector in Finland. Participants: Among ambulat ory patients aged 45 to 89 years who had no history of coronary disease, we defi ned new cases of “nitrate angina”based on nitrate prescription(56 441 women an d 34 885 men) or “test-positive angina”based on abnormal invasive or noninvas ive test results(11 391 women and 15 806 men). Potentially eligible patients wer e evaluated between January 1, 1996, and December 31, 1998. Follow-up ended in December 2001. Main Outcome Measures: Coronary mortality at 4 years(n=7906 death s) and fatal and nonfatal myocardial infarction at 1 year(n=3129 events). Results: The age-standardized annual incidence per 100 population of all cases of ang ina was 2.03 in men and 1.89 in women, with a sex ratio of 1.07(95%confidence i nterval[CI], 1.06-1.09). At every age, nitrate angina in women and men was asso ciated with a similar increase in risk of coronary mortality relative to the gen eral population. Women with test-positive angina who were younger than 75 years had higher coronary-standardized mortality ratios than men; for example, among those aged 55 to 64 years, it was 4.69(95%CI, 3.60-6.11) in women compared wi th 2.40(95%CI, 2.11-2.73) in men(P< .001 for interaction). There was a strong, graded relationship between amount of nitrates used and event rates; women usin g higher doses of nitrates had prognoses comparable with those of men. Among pat ients with diabetes and test-positive angina, age-standardized coronary event rates were 9.9 per 100 person-years in women vs 9.3 in men(P=.69), and the full y adjusted male-female sex ratio was 1.07(95%CI, 0.81-1.41). Conclusions: Wom en have a similarly high incidence of stable angina compared with men. Furthermo re, stable angina in women is associated with increased coronary mortality relat ive to women in the general population and, among easily identifiable clinical s ubgroups, has similarly high absolute rates of prognostic outcomes compared with men. Context: Stable angina pectoris in women has often been considered a “soft” d iagnosis, with less-severe prognostic implications than in men, but large-scal e population studies are lacking. Objective: To determine sex differences in the incidence and prognosis of Desi gn: Prospective cohort study using linked national registers. Setting: All munic ipal primary health care centers, hospital outpatient clinics, occupational heal th care services, and private sector in Finland. Participants: Among ambulat ory patients aged 45 to 89 years who had no history of coronary disease, we defi ned new cases of “nitrate angina” based on nitrate prescription (56 441 women an d 34 885 men) or “test-positive angina” based on abnormal invasive or noninvasive test results (11 391 women and 15 806 men). Potentially eligible patients wer e evaluated between January 1, 1996, and December 31, 1998. Follow-up ended in December 2001. Main Outcome Me as: Coronary mortality at 4 years (n = 7906 deaths) and fatal and nonfatal myocardial infarction at 1 year (n = 3129 events). Results: The age-standardized annual incidence per 100 population of all cases of ang ina was 2.03 in men and 1.89 in women, with a sex ratio of 1.07 (95% confidence i nterval [CI], 1.06-1.09). At every age, nitrate angina in women and men was asso ciated with a similar increase in risk of coronary mortality to the gen eral population. Women with test-positive angina who were younger than 75 years had higher coronary-standardized mortality ratios than men; for example, among those aged 55 to 64 years, it was 4.69 (95% CI, 3.60-6.11 ) in women compared wi th 2.40 (95% CI, 2.11-2.73) in men (P <.001 for interaction). There was a strong, graded relationship between amount of nitrates used and event rates; women usin g higher doses of nitrates had prognoses comparable with those of men. Among patients with diabetes and test-positive angina, age-standardized coronary event rateswere 9.9 per 100 person-years in women vs 9.3 in men (P = .69), and the full adjusted male-female sex ratio was 1.07 (95% CI, 0.81-1.41). Conclusions: Wom en have a similarly high incidence of stable angina compared with men. Furthermo re, stable angina in women is the associated with increased coronary mortality relat ive to women in the general population and, among readily identifiable clinical s ubgroups, similarly similarly high in prognostic outcomes compared with men.