Background. In recent years there has been a dramatic increase in the use of breast conservation therapy for patients with cancer. There are several factors associated with local recurrence but none are considered absolute contraindication for breast conserving therapy except multifocal carcinoma. This single-institution series investigates the effects of multiple factors on local relapse-free survival after breast-conserving therapy for women with invasive cancer. Methods. One-hundred and ninety-two patients (193 cancers) with invasive carcinoma underwent breast-conserving therapy (surgery, radiation therapy and chemotherapy if indicated) at University of Alabama at Birmingham Hospital from 1986 through 1995. The Kaplan-Meier method was used to calculate curves for local recurrence. The log rank statistic test was used for statistical comparison between curves. The Cox proportional hazards model was used for multivariate analysis. Significance was defined as p < 0.05. Results. Mean patient age was 56 ± 12 years (range 25-83 years). Nineteen patients (9.8%) were 40 years age or younger. With a median time follow-up of 67 months the local recurrence rate for all patients was 6.7%. Ten patients developed local recurrence and three had combined local and distant recurrence. The mean local relapse-free interval was 71 months (range 10-148). The 5-year actuarial local relapse-free survival for all patients was 96%. Comparison of patients younger and older than 40 years age revealed a significantly lower risk of recurrence with increasing age (86 vs. 97% respectively, p = 0.013). Patients 40 years age or younger with poorly differentiated tumors had a 5-year local relapse-free survival of only 40%. In multivariate analysis, only young age and poor tumor differentiation were found statistically significant in predicting local recurrence. Conclusions. Age and tumor differentiation are independent risk factors in our serie. These two factors should be taken into consideration when counseling breast cancer patients.