The aim of this study was two-fold. The first aim was to determine the levels of critical thinking disposition and perception of problem-solving ability of pre-service teachers. The second aim was to compare the effects of problem-based learning and traditional teaching methods on the critical thinking dispositions and perceptions of problem-solving ability of pre-service teachers, when implemented in the teaching of the acid-base topic. Participants for the study consisted of 49 pre-service teachers. A pre-test-post-test control group design was used. Data were obtained using the California Critical Thinking Disposition Inventory and Problem-Solving Inventory. It was generally determined that pre-service teachers exhibit low levels of critical thinking disposition and medium levels of perception of problem-solving ability. Also, while problem-based learning and traditional teaching methods did not have different effects on the critical thinking dispositions of pre-service teachers, they had different effects on their perceptions of problem-solving ability.