Since 1960 more than 3000 consecutive patients with operable infiltrating breast carcinoma were treated by radiation therapy with or without primary limited surgery, which usually consisted of local excision. For tumors smaller than or equal to 5 cm the ten-year crude survival rate is 77% for patients without palpable axillary nodes (T1-2N0) and 63% for patients having axillary adenopathy (T1-2N0). For operable tumors exceeding 5 cm of diameter (T3N0-1) the ten-year crude survival is 34%. Thirty-five percent of the patients alive free of disease at ten years required a secondary operation for presumed local or regional tumor persistence or recurrence, although no residual disease was found in 24% of the operative specimens. Local-regional recurrence had no adverse effect on ten-year survival. This conservative approach offers most women with operable breast cancer an excellent chance at breast preservation with the same chance for ten-year survival as with radical mastectomy.