his study entitled “study to assess the knowledge level on ill effects of air pollution among students in selected high schools at Salempur”submitted in the year 2024. Aims: The objectives are to assess the knowledge level on ill effects of air pollution among students in selected schools at Salempur; to determine the association between the knowledge with the socio demographic variables. Hypothesis: There is a significant association between the level of knowledge with socio demographic variables. Design and setting: Quantitative approach descriptive design was used. Total 30 students were selected from selected high schools at Salempur. Methods and materials: Convenient sampling technique was used to select 30 participants. Structured questionnaire was used to collect the data. The results of this study revealed that most of students 60% had moderate level of knowledge and 40% had adequate knowledge about air pollution and interestingly no students scored inadequate knowledge and concluded that, there is a need to motivate the students to spread awareness on air pollution and its ill effects and should change the behavior of people.