The identification of factors associated with breast recurrence as first event (62 cases, 10%) following conservative surgery and radiation therapy are drawn out from a series++ of 618 mammary carcinomas of clinical size less than 40 mm, stage I and II (UICC), with a median follow up of 8 years. The most powerful predictive characteristic associated with the likelihood of breast recurrence is multiple foci of invasion (42.9% vs 8.9, P = 0.0001, relative risk [RR]: 6). After this rarely cited feature, young age, less than 40 years (20% vs 7.3%, P = 0.0001, RR: 2.8), extensive in situ carcinoma more than 25% (19.2% vs 8.7%, P = 0.003, RR: 2.5) were found also persistent in the Cox model, but not histologic size more than 25 mm (18.9% vs 9.1%, P = 0.01, RR: 2.3). The site of recurrence was studied on the 54 salvage mastectomy done. A high rate of recurrence at distance of the initial site was found: 37% whose more than half, 22%, were multicentric. No significant difference in the mean delay of appearance was noted between recurrence near or at distance of the initial cancer (mean delay 52 months vs 64 months). From the recurrence the evolution is not very favourable: excluding simultaneous metastases found at the preoperative investigation, ten cases, mammary recurrence is followed by a metastatic syndrome in 36% of cases against 17% without it (P = 0.01, RR: 1.9). Metastatic evolution is not significantly linked with the time, early or late, of the mammary recurrence (54.5% before 5 years vs 39% after) but with the association of a controlateral cancer (P = 0.03). Locally ten of the 54 mastectomy presented a thoracic recurrence, often in case of multicentric breast recurrence (P = 0.05) and not significantly when skin or areola were invaded by carcinoma.