Purpose: To examine the effect of clinical presentation and interval to breast surgery on local recurrence and survival in early-stage breast cancer. Methods and materials: The data from 397 patients with Stage T1-T2N0 breast carcinoma treated with conservative surgery and breast radiotherapy between 1985 and 1992 were reviewed at the London Regional Cancer Program. The clinical presentation consisted of a mammogram finding or a palpable lump. The intervals from clinical presentation to definitive breast surgery used for analysis were 0-4, >4-12, and >12 weeks. The Kaplan-Meier estimates of the time to local recurrence, disease-free survival, and cause-specific survival were determined for the three groups. Cox regression analysis was used to evaluate the effect of clinical presentation and interval to definitive surgery on survival. Results: The median follow-up was 11.2 years. No statistically significant difference was found in local recurrence as a function of the interval to definitive surgery (p = .424). A significant difference was noted in disease-free survival (p = .040) and cause-specific survival (p = .006) with an interval of >12 weeks to definitive breast surgery. However, the interval to definitive surgery was dependent on the presentation for cause-specific survival, with a substantial effect for patients with a mammographic presentation and a negligible effect for patients with a lump presentation (interaction p = .041). Conclusion: The results of this study suggest that an interval of >12 weeks to breast surgery might be associated with decreased survival for patients with a mammographic presentation, but it appeared to have no effect on survival for patients presenting with a palpable breast lump.