OBJECTIVES: Limited research exists addressing issues of website development and attitudes towards websites that promote physical activity. This paper describes the design and process evaluation of a physical activity intervention, from a randomised trial (RT) that examined the effectiveness of delivery modes (face-to-face, Internet-mediated (combined Internet and face-to-face) and Internet-only). METHODS: Evaluation surveys were completed at the end of the RT intervention (n=159), and a random sample (n=23) participated in focus group discussions. Differences were assessed using ANOVA, t-tests, and qualitative analysis. RESULTS: Face-to-face participants were more satisfied with their group allocation than the Internet groups. Internet groups reported accessing the Internet at home, and that they liked the self-paced nature of the website. Difficulties associated with time and motivation were raised by the Internet groups. No differences were found for content acceptability and credibility. Website usability scores were high for both Internet groups. CONCLUSION: These findings support the use of the Internet in terms of content satisfaction and usability; however, issues were raised regarding the acceptability of an Internet-based program when traditional face-to-face delivery options are available. PRACTICE IMPLICATIONS: Identifying avenues to support user perceptions of 'motivation', and mechanisms for enhancing engagement and retention, and user acceptability are required.