Seventy cases of infiltrating lobular (IL) carcinoma of the breast presenting to Hahnemann University Hospital between 1965 and 1990 were reported. This comprised 2.4 per cent of the total number of breast cancer cases during that time period. Fifty-seven of these tumors were pure IL carcinoma, while 13 had both IL and infiltrating ductal characteristics. Two-year, 5-year, and 10-year survival rates were not influenced by stage at the time of presentation, histology, nor operation performed. Though a statistically significant trend toward breast conservation surgery was documented over time, there was no significant relationship between operation performed and survival. This was true for both localized and nodal-metastatic disease. Overall survival was essentially equivalent to that reported for infiltrating ductal carcinoma.