The aim of this research was to investigate the effects of peer instruction on learning strategies, problem solving performance, and conceptual understanding of college students in a general chemistry course. The research was performed students enrolled in experimental and control groups of a chemistry course were selected. Students in the experimental group instructed with peer instruction, while students in the control group instructed by conventional instruction. The research data were collected with chemistry achievement test, learning strategy survey, an examination, and student evaluation questionnaire. The results revealed that the students' conceptual understanding, learning strategies, and problem solving performance in the experimental group improved significantly relative to the students in the control group. The students also changed their perspective on comprehending a concept and solving a problem and enhanced their learning strategies (cognitive/metacognitive strategies and resource management strategies) with peer instruction in the experimental group.