BACKGROUND: The Internet is a major source of information for the general public in the field of health. However despite ever-increasing connection rates, a digital divide persists in the industrialised countries. The objective of this study was to assess the determinants involved in Internet access and then in Internet use for health information seeking. METHODS: This study is based on a cross-sectional survey of a representative random sample of French inhabitants: the Enquête permanente sur les conditions de vie des ménages conducted by Insee in 2005, which included a specific investigation on information and communication technology. RESULTS: Fifty-two percent of the French adult population had Internet access, and 28.5% of the Internet users had previously searched for medical information during the month before the survey. A first level of socioeconomic divide has been shown in Internet access: poor socioeconomic status, health problems. In terms of health information seeking among Internet users, the divide was not socioeconomic but more related to gender, the health care system utilization, and the diversified use of the Internet. CONCLUSION: In a public health perspective, this study suggests that promoting Internet access and utilization is still necessary in order to make it a widely used tool for prevention and health promotion.