Equity in health care delivery is one of the objectives of the Portuguese health care system. To date, research on this issue has mainly focused on income-related equity. This is the first study to shed light on gender equity, using a large data base that includes all patients admitted with cardiac heart disease at Portuguese NHS hospitals over the 2000-2006 period (259,519 discharges from 57 hospitals). In this paper we compare the use of catheterization and revascularization between men and women, controlling for age, comorbidities and hospital characteristics. Our findings show that women receive notably less catheterization and revascularization, with no significant change in this pattern over the 2000-2006 period. In addition, we observe that (i) gender differences disfavouring women are higher prior to detection of acute disease than after; (ii) women are significantly more likely to die during hospitalization despite equal treatment; (iii) gender differences against women are higher for non-elective admissions, and women are more often admitted through emergency units. These additional findings suggest that gender differences in detection, referral and treatment at early stages of the disease are likely to play a crucial role. They could possibly explain part of the higher gender differences before acute disease has been detected; they also lead women to be treated later, to be more frequently admitted through emergency units and to experience worse outcomes. However, alternative explanations cannot be discarded. The higher women's in-patient mortality may also signal gender differences in recovery from treatment, and the higher gap among emergency admissions could point to women's lower willingness to be treated. Further investigation should help to disentangle the precise role of each of these causal factors. (C) 2010 Elsevier Ltd. All rights reserved.