Patient navigation is a process that provides assistance to referring physicians in arranging further investigations and consultation for defined patient groups. This can facilitate timely investigations and potentially minimize delays. The purpose of this study was to determine the impact of patient navigation on timeliness in the diagnosis of breast abnormalities. We retrospectively studied a cohort of 536 women who underwent breast core biopsy at our institution during comparable 6-month periods in 1999 and 2000 to determine the effects of patient navigation, age, and biopsy result on the wait for a biopsy after diagnostic imaging. Patient navigation was used for all women referred through the provincial breast cancer screening program. Navigation was unavailable to patients directly referred by physicians in 1999. In 2000, the program was expanded to encompass all patients. From 1999 to 2000, the median wait for a biopsy remained relatively stable for "navigated" screening patients at 12 days (n = 97) and 13 days (n = 133), respectively. The introduction of patient navigation for directly referred patients resulted in a statistically significant decrease in waiting times, from 20 days (n = 144) in 1999 to 14 days (n = 162) in 2000. Age and biopsy results were statistically significant variables, but their effect on the group data was negligible relative to that of navigation. Patient navigation significantly improves timeliness in the diagnosis of breast abnormalities and can potentially improve quality of life with more timely reassurance for women with benign conditions and earlier treatment for those with malignancy.