The presence of positive surgical margins is a negative prognostic indicator in patients undergoing prostatectomy for prostate cancer; whether the extent of the positive margins affects the clinical outcome with regards to prostate-specific antigen (PSA) recurrence remains uncertain. We evaluated the linear extent of margin positivity as a prognostic indicator in a series of radical prostatectomy specimens. One hundred seventy-four consecutive margin-positive prostatectomy specimens were evaluated. The linear extent of margin positivity was measured with an ocular micrometer and ranged from 0.05 to 75.0 mm (mean, 8.94; median, 5.0). The linear extent of margin positivity was associated with tumor volume (P = .03) but was not associated with patients' age at surgery, preoperative PSA level, prostate weight, pathologic stage, Gleason score, extraprostatic extension, seminal vesicle invasion, perineural invasion, high-grade prostatic intraepithelial neoplasia, or PSA recurrence. In the full model multiple Cox regression, significant predictors for PSA recurrence were Gleason score (P = .001) and preoperative PSA (P = .01); extent of margin positivity was not predictive of PSA recurrence (hazard ratio, 1.00; 95% confidence interval, 0.98-1.02; P = .97) nor was tumor volume a significant factor when adjusted for other covariates (P = .27). Preoperative PSA, tumor stage, and Gleason score remained significant prognostic factors in evaluating the likelihood of PSA recurrence in patients with positive surgical margins; the extent of margin positivity, however, is not a prognostic factor for PSA recurrence and should, therefore, not necessarily be included in the final report for radical prostatectomy specimens.