Background and objectives: Due to wide spread use of the Global System for Mobile Communications (GSM) mobile phones they have become indispensable as communication tools and any consequent in biological effects should be important  as a high-priority environmental health issue. Their use without any knowledge of their harmful effects is unsafe.  The objectives of this study was to findout Knowledge regarding health hazards on cell phone use among Higher Secondary Level Students, Birgunj. Materials and methods: A descriptive cross sectional research design was used. Sample size was 111 higher secondary level students.  Non-probability sampling techniques was used to selected College and class XI and XII. Whereas, 750 students were class XI with 8 section and class run in morning and day shift. Similarly, class XII had 700 students with 6 section and class run in morning and day shift. Out of 1450 students, 61 students from grade XI and 50 students from grade XII, altogether 111 students were selected respectively by using Stratified Sampling technique from proportionate method. Self- Administered Questionnaire was used for data collection. Data entry and analysis was done in SPSS version 17. Data was analyzed by using descriptive (frequency, percentage, mean) and inferential statistics (chi square test) to identify association between level of knowledge with selected variables. Results: The finding of the study showed that all most (89.2%) respondents had poor level of knowledge and only 12 (10.8%) respondents had average level of knowledge. Almost all (98.2%) respondents had cell phone among them 78 (71.6%) have smart phone. In the inferential statistics there were statistically significant association (p<0.05) between level of knowledge and grade (0.003). Conclusion: This study concluded that knowledge regarding health hazards on cell phone use is poor among higher secondary level students. Some educational intervention need to organized on this topic by giving different programs on television, radio, newspaper, and internet to discourage unhealthy practice of cell phone.