Assertiveness is a vital psychosocial skill that enables adolescents to express their thoughts, emotions, and beliefs confidently while respecting the rights of others. During adolescence, individuals face numerous challenges such as academic pressure, peer influence, and emotional changes, which can significantly affect their ability to communicate effectively. Inadequate assertiveness may lead to low self-esteem, anxiety, poor decision-making, academic stress, and vulnerability to negative peer pressure. Schools serve as crucial environments for nurturing life skills like assertiveness, making it essential to assess assertive behavior among school-going adolescents. The present study aimed to assess the level of assertive behavior among adolescents aged 13–16 years and to determine its association with selected socio-demographic variables. A quantitative, descriptive research approach was adopted for the study. The research was conducted at Campion Higher Secondary School, Bhouri, Bhopal. A total of 100 adolescents were selected using a non-probability purposive sampling technique. Data were collected using a structured socio-demographic questionnaire and the standardized Rathus Assertiveness Scale (RAS). The findings revealed that 68% of adolescents demonstrated assertive behavior, 32% showed aggressive behavior, and none were categorized as non-assertive. The mean assertiveness score was 19.81 with a standard deviation of 18.699, indicating a statistically significant level of assertive behavior among the participants (p < 0.001). Chi-square analysis was performed to assess the association between assertive behavior and selected demographic variables. The results showed a statistically significant association between assertive behavior and fathers’ education, mothers’ education, and fathers’ occupation. However, no significant association was found between assertive behavior and other variables such as age, gender, religion, family income, year of study, stream of study, residential status, type of family, mothers’ occupation, and source of previous knowledge. The study concludes that parental educational and occupational status plays a significant role in shaping assertive behavior among adolescents. The findings highlight the need for structured assertiveness training programs in schools to strengthen adolescents’ communication skills, self-confidence, and emotional well-being. Early identification and intervention can contribute to healthier interpersonal relationships and improved psychosocial development among adolescents.