Because nasopharyngeal carcinoma (NPC) has a close association with Epstein-Barr virus (EBV), measuring serum EBV DNA and anti-EBV serum marker concentrations could be a feasible method for NPC diagnosis, monitoring and probably screening especially in a community at risk. The aim of this study was to determine the EBV pattern in sporadic NPC and in high risk NPC Tunisian families in order to evaluate their risk factors and help for NPC screening. The rates of anti-EBV antibodies and EBV DNA were determined in the serum of 47 healthy members randomly selected from 23 NPC multiplex families with two or more affected members, 93 healthy Tunisian community controls chosen with the same age, sex and geographic origin as unaffected individuals and 66 EBV positive sporadic NPC patients whose serum was available before and after treatment. Unexpectedly, significant lower concentrations of anti-EA (Early Antigen) IgG and anti-VCA (Viral Capsid Antigen) IgG were found in unaffected members from NPC families than in healthy controls while viral loads were negative in all the tested sera. For sporadic NPC patients, anti-EA IgG and anti-VCA IgA concentrations were significantly higher than in healthy controls and these rates decreased after treatment. The level of EBV DNA load varied according to the condition of the tumour. This study suggests that in the Tunisian NPC families, screening for malignancy is based on serum concentrations but not on EBV DNA load while in the sporadic NPC group, serologic markers and EBV DNA load are complementary for diagnosis and follow-up.