BACKGROUND: This study prospectively examines the prognostic role of p53 oncoprotein (p53), Ki67-antigen (Ki67), tumor angiogenesis (MVD), epidermal growth factor receptor (EGFR), and HER2 receptor protein (HER2) expression in Chinese with undifferentiated nasopharyngeal carcinoma (NPC). METHODS: Seventy-eight Chinese were recruited from October 1995 to July 1997 at the Prince of Wales Hospital, Hong Kong. Pretreatment immunohistochemical preparations of the primary tumor were made, and clinical data were collected prospectively until October 30, 2000. The markers were correlated with overall survival (OS), disease-free survival (DFS), time to progression (TTP), and UICC stage. RESULTS: On univariate analysis, EGFR expression correlated with poorer OS (p =.0001), DFS (p =.01), shorter TTP (p =.0001), and advanced T stage (p =.036). Strong EGFR expression, when compared with weak or moderate, was associated with poorer OS (p =.04) and shorter TTP in a subgroup of patients with UICC stage III-IV disease. HER2 expression was associated with advanced UICC stage (p =.006). The presence of p53 expression correlated with poorer DFS (p =.01) and a trend toward shorter TTP (p =.06). No correlation was found with Ki67-antigen or MVD. On multivariate analysis, only EGFR expression was significantly linked to shorter OS and TTP. CONCLUSIONS: EGFR expression in undifferentiated NPC is associated with a poor clinical outcome. A prognostic role of p53 and HER2 expression is suggestive but not consistently defined in this study. The relatively high prevalence of positive staining for EGFR supports the use of molecular targeted therapy in this disease.