Delay in follow-up after an abnormal mammogram is associated with advanced disease stage, poorer survival, and increased anxiety. Despite the implementation of many patient navigator programs across the country, there are few published, peer-reviewed studies documenting its effectiveness. We tested the effectiveness of a patient navigator in improving timeliness to diagnosis, decreasing anxiety, and increasing satisfaction in urban minority women after an abnormal mammogram. Women with suspicious mammograms were randomly assigned to usual care (N=50) or usual care plus intervention with a patient navigator (N=55). There were no demographic differences between the two groups. Women in the intervention group had shorter times to diagnostic resolution (mean 25.0 vs. 42.7 days; p=.001), with 22% of women in the control group without a final diagnosis at 60 days vs. 6% in the intervention group. The intervention group also had lower mean anxiety scores (decrease of 8.0 in intervention vs. increase of 5.8 in control; p<.001), and higher mean satisfaction scores (4.3 vs. 2.9; p<.001). Patient navigation is an effective strategy to improve timely diagnostic resolution, significantly decrease anxiety, and increase patient satisfaction among urban minority women with abnormal mammograms.