Background: Chronic hepatitis B virus infection (HBV) is an important health problem in the Turkish community in the Netherlands, and promotion of screening for HBV in this risk group is necessary. An individually tailored intervention and a culturally tailored intervention have been developed to promote screening in first generation 16-40 year old Turkish immigrants. This paper describes the design of the randomized controlled trial, which will be used to evaluate the effectiveness of the two tailored internet interventions as compared to generic online information on HBV, and to assess the added value of tailoring on socio-cultural factors. Methods/Design: A cluster randomized controlled trial design, in which we invite all Rotterdam registered inhabitants born in Turkey, aged 16-40 (n = 10,000), to visit the intervention website is used. A cluster includes all persons living at one house address. The clusters are randomly assigned to either group A, B or C. On the website, persons eligible for testing will be selected through a series of exclusion questions and will then continue in the randomly assigned intervention group. Group A will receive generic information on HBV. Group B will receive individually tailored information related to social-cognitive determinants of screening. Group C will receive culturally tailored information which, next to social-cognitive factors, addresses cultural factors related to screening. Subsequently, participants may obtain a laboratory form, with which they can be tested free of charge at local health centres. The main outcome of the study is the percentage of eligible persons tested for HBV through to participation in one of the three groups. Measurements of the outcome behaviour and its determinants will be at baseline and five weeks post-intervention. Discussion: This trial will provide information on the effectiveness of a culturally tailored internet intervention promoting HBV-screening in first generation Turkish immigrants in the Netherlands, aged 16-40. The results ...