To ascertain the prognostic significance of tumor hormone receptor status in node negative, premenopausal patients with breast cancer, a retrospective view of 199 patients fitting these criteria was conducted. Of these 199 patients, 147 had estrogen receptor data available. There were 104 patients (71%) who were estrogen receptor negative, and 16 (15%) had developed local or distant recurrence with a median follow-up of 44 months. Five patients had died of breast cancer. Of the 43 patients who were estrogen receptor positive, there was one recurrence, and no breast cancer deaths. This difference in recurrence is statistically significant (P less than 0.01) by the log-rank probability test. Of the 17 patients with recurrent disease, 14 (82%) had primary tumors 2 cm or larger in size. If only those patients with tumors 2 cm or larger are considered, 23% (13/57) who were estrogen receptor negative and 5% (1/19) who were estrogen receptor positive recurred. This remains statistically significant (P less than 0.025). We conclude that tumor hormone receptor status and size of tumor are significant prognostic factors in identifying premenopausal, node negative women at risk for recurrent disease.