Background: Public health nurses (PHNs) often cannot receive in-service education due to limitations of time and space. Learning through the Internet has been a widely used technique in many professional and clinical nursing fields. The learner's attitude is the most important indicator that promotes learning. Objectives: The purpose of this study was to investigate PHNs' attitude toward web-based learning and its determinants. Design: This study conducted a cross-sectional research design. Settings: 369 health centers in Taiwan. Participants: The population involved this study was 2398 PHNs, and we used random sampling from this population. Finally, 329 PHNs completed the questionnaire, with a response rate of 84.0%. Methods: Data were collected by mailing the questionnaire. Results: Most PHNs revealed a positive attitude toward web-based learning (mean±SD=55.02±6.39). PHNs who worked at village health centers, a service population less than 10,000, PHNs who had access to computer facility and on-line hardware in health centers and with better computer competence revealed more positive attitudes (p < 0.01). Conclusions: Web-based learning is an important new way of in-service education; however, its success and hindering factors require further investigation. Individual computer competence is the main target for improvement, and educators should also consider how to establish a user-friendly learning environment on the Internet.