We undertook a large retrospective study to evaluate the impact of screening family members of NPC patients with Epstein Barr Virus (EBV) serology. 1,199 asymptomatic family members of NPC patients were entered into the annual screening program with EBV serology and nasopharyngoscopy between 1994 and 2005. Eighteen participants of our screening program developed NPC; 17 of them were treated in our institute, of whom 16 were detected in screening. The sensitivity and specificity of EBV serology were 83.3 and 87.0%, respectively, and for the program they were 88.9 and 87.0%, respectively. Stage distributions and survival outcomes of the 17 cases were compared with that of 1,185 consecutive symptomatic patients diagnosed in the same period through general referral. It was found that the screening program resulted in early detection of cancer, with 59% presenting at early stage (stage I: 41%, stage II: 18%) compared to 24% (stage I: < 1%, stage II: 23%) of symptomatic cancers (P < 0.001), and a significant improvement in disease-free survival (P = 0.04). The cancer specific survival and overall survival rate at 5-year are also higher (92 vs. 77% and 92 vs. 70%, respectively), though they fail to reach statistical significance. In conclusion, screening asymptomatic family members of NPC patients annually leads to earlier detection of NPC and clinically valuable survival advantage among these family members. A larger sample size is needed to confirm its full potential in survival benefit.