The prognostic significance of biologic markers in women with ductal carcinoma in situ is not fully understood. HER2/neu is a marker of prognostic significance that is routinely assessed in invasive cancer but its correlation with clinical outcome in DCIS is still obscure.To evaluate the significance of HER-2/neu expression as a prognostic marker in DCIS.Clinical and pathologic data from 84 patients treated for DCIS were analyzed. HER-2/neu expression was determined by immunohistochemical staining. Histopathologic parameters (nuclear grade, histologic subtype, necrosis, calcifications, margins) were reviewed by an experienced pathologist. Local recurrence and/or metastatic spread were used as endpoints to determine the prognostic significance of HER-2/neu expression.With a median follow-up of 94.8 months, nine recurrences were reported. Neither univariate nor multivariate analysis showed a significant correlation between HER-2/neu expression and disease recurrence or the time to disease recurrence. Although HER-2/neu expression demonstrated a significant association with high nuclear grade (P < 0.0001) and comedo subtype (P < 0.0001), there was no correlation between these histologic features and recurrence rate. The correlation between high nuclear grade and disease recurrence approached statistical significance (P = 0.07).No significant association was found between HER-2/neu expression in DCIS and disease recurrence. However, HER-2/neu correlated with negative markers such as nuclear grading and comedo necrosis, and its role should therefore be investigated in larger studies.