Problem-based learning (PBL) is often promoted in response to the current need of offering authentic and effective professional education. Traditionally, PBL is used in face-to-face learning environments, with a facilitator guiding collaborative teams of students in solving a problem. This article reports the use of PBL in Web-based instruction and describes how this approach differs from traditional Web-based learning. The content of students' discussions is analyzed, as is their performance and affective responses toward the Web-based learning. Due to the use of problem scenarios in PBL treatment, students tended to go through a deeper process in analyzing, choosing, and determining the topic of interest. In students' final projects and discussions, more description of different dimensions of related issues was discussed among the PBL groups.