This study examined the relationship between problem-solving ability and study behavior of secondary school students in Southwestern Nigeria. A total of 430 SS 3 students randomly selected from fifteen secondary schools in Southwestern Nigeria participated in the study. A Problem-Solving Inventory and a Study Behaviour Inventory were employed in the data collection from the respondents. Multiple Regression Analysis was used to treat the data. The results obtained indicated that problem-solving ability was significantly predictive of study behavior. Implications for counselors to use problem-solving activities in improving students' study behaviors were discussed. (Contains 3 tables.)