Web-Based Instruction is increasingly being recognized as a means of teaching and learning. In dietetics, the interactions between drugs and nutrients are complex due to the wide variety of drugs and their mechanism and interactions with nutrients. How to help student professionals acquired necessary skills and knowledge is important in a dietetic training program. This paper proposed an integrated problem-based learning (PBL) approach in a web-based context to help students acquire knowledge. Important aspects of the PBL framework such as the use of problem sets, instructional contents, basic knowledge, exploration, facilitator, and scaffolding were discussed. The application of the PBL approach to a web-based instruction was implemented and evaluated. Students' responses were gathered from different aspects, including: instructional functions, use of resources, use of discussion, and assignment. (Contains 1 figure and 6 tables.)