The importance of steroid receptors for the prognosis of mammary carcinoma has been evaluated by investigating the course of disease in 163 patients for a median follow up time of 66 months after mastectomy. Multivariate analysis including estrogen receptor (ER), progesterone receptor (PgR), the presence of 8S and 4S ER together or 4S ER only, and the lymph node status revealed only the latter to have significant (p less than 0.001) predictive potency. Lymph node positive (N-pos) patients had a 3.3 (1.7-6.2) fold risk of death and 2.8 (1.7-4.7) fold risk of recurrence relative to node negative (N-neg) patients. When we compared overall survival (OAS) and disease-free survival (DFS) in the various receptor-positive groups with the groups that displayed neither ER nor PgR, significant differences in prognosis were only seen in N-neg patients. PgR did not turn out to be a better prognostic factor than ER, nor was the 8S ER a sign of increased OAS and DFS compared to total ER. However, the number of patients in this group was too small to allow a definite statement.