A program to ensure an equivalent standard of care for all patients with breast cancer was initiated in the Stockholm area in the mid 1970s. As part of an evaluation of this program, social gradients in clinical stage at presentation and survival were analyzed among patients diagnosed during 1977 through 1997. The patients (n = 15,021) were selected from a database covering about 88% of all diagnosed breast cancer cases in the region. Putative associations were analyzed between clinical stage, survival and different socioeconomic indicators (level of education, income and occupation). There were significant social differences (p < 0.01) in distribution of clinical stage as well as in total and stage-specific survival. High income, more skilled work and a high level of education were all associated with clinically less advanced tumors and hence better survival. However, stage-specific survival differences were mostly generated by differences in nonbreast cancer mortality. The results indicate social inequalities regarding awareness of the disease and/or access to early detection. Social gradients in nonbreast cancer mortality were also found to influence observed survival. In contrast, we observed no significant social differences in stage-specific breast cancer mortality.