Although the Web is almost omnipresent in many children's lives, most children lack adequate Web searching skills as well as skills to process and critically evaluate Web information. In this article, we describe and evaluate an educational program that aimed at acquiring Web skills in the context of a content knowledge domain. Through a multiple case study design we wanted to gain insight into the contextual factors that influence the realization of such program and into the learning gains in the participating classes in terms of content knowledge and Web skills. Four 5th grade teachers carried out the program, which consisted of eight weekly sessions and focused on teaching students Web searching, reading and evaluating skills within the subject of healthy food. Data from a variety of sources were collected: videotaped and written lesson observations, interviews with teachers and students, teacher diaries, student questionnaires and student assignments. The results show that the teachers appeared to be able to carry out the program to varying degrees. Contextual factors that influenced the realization of the program were partly related to specific conditions as the investment of time and effort by the teacher and the school's way of organizing computer work and its supervision. The extent to which teachers' teaching styles corresponded with the program's assumptions also played an important role. Students' knowledge and skills improved during the program with regard to both content knowledge and Web skills. However, most students appeared to remain inconsistent Web users, and did not act upon their knowledge of Web searching, reading and evaluating skills. Although generally speaking there were differences between stronger and weaker performing students, all students showed unexpected, inconsistent or inflexible behavior. © 2007 Elsevier Ltd. All rights reserved.