Sex differences have been observed in the clinical profile, prognosis, and treatment of patients with unstable ischemic heart disease. Men tend to receive more invasive management. We assessed these differences in 823 consecutive patients (543 men) with possible acute coronary syndrome without ST-segment elevation who were seen since our chest pain unit opened. A protocol for the management of unstable ischemic heart disease was followed. Women had a worse baseline clinical profile but men more frequently had a positive exercise stress test. Univariate analysis showed that angiography and revascularization procedures were performed more often in men. However, multivariate analysis did not confirm male sex as an independent predictor of the need for a more invasive strategy. The inauguration of a chest pain unit and application of a protocol for the management of unstable ischemic heart disease has helped to correct case stratification and optimize the application of invasive treatments.