Problem-based learning (PBL) is a constructivist pedagogical approach to learning in which students work together to find solutions to a complex problem. This study used a mixed-method approach to examine the impact of PBL on student attitudes toward science, problem-solving skills and their perceptions of the learning environment. Forty-eight students in three regular high school chemistry classes participated in the study. Results based on student answers to a survey questionnaire, journal entries, approaches to solving a problem, and teacher classroom observations indicated a significant increase in student attitudes toward science, problem-solving skills and positive views of the learning environment. The use of PBL also facilitated the development of a sense of community in the classroom. (Contains 4 tables.)