The present study was conducted to find out the role of classroom environment and self-concept in the academic achievement of boys and girls in Malayalam medium secondary schools. The sample for the study was collected from various schools of Kozhikode district in the state of Kerala. Sample consists of 300 secondary school students of which 162 are boys and 138 are girls. Different standardized tools were used to measure the classroom environment and parental involvement; and the score of the annual examination was taken as the indicator of academic achievement. Mean standard deviation, t-test, z-test and stepwise regression analysis were used for analyzing data. The study revealed that both the variables significantly predict the academic achievement of boys and girls. Classroom environment is the highest predictor for both the groups and self-concept follows it in the prediction.