This study investigates the effect of Problem Based Learning (PBL), a constructivist teaching strategy, on achievement in physics and attitude towards physics. Cognitive styles of students have been taken as classifying variable to include learning condition in the context of study. The sample of the study included 115 11th class students of the Government School of Chandigarh. Two classes of same school were randomly selected as experimental and control groups. The study was quasi experimental in nature. 2x2 between-subject design with pre-test post-test control group condition was used to study interaction and main effects of independent (teaching method) and classifying variable (cognitive style) on dependent variable (achievement in physics). 2- way ANOVA was mainly used as statistical technique to analyze data quantitatively. The experimental results indicated that PBL group students outperformed LBL (Lecture Based Learning) group students on achievement in physics. Even though interaction effect of teaching method and cognitive styles was not significant for achievement in physics and attitude towards physics. No significant difference between field independent and field dependent cognitive style students on achievement in physics. Moreover, implications, limitations of the present study, and recommendations for further studies are also discussed.