Objective: To study the prevalence and correlates of self-reported ADHD symptoms among school-going adolescents from Kerala, India. Method: Seven thousand five hundred sixty students from Classes 8, 10, and 12, aged 12 to 19 years, across 73 schools selected by cluster random sampling, were invited to participate, but only 7,150 successfully completed the questionnaire incorporating standardized instruments. Results: Three hundred five (4.3%) self-reported symptoms for ADHD combined type, 131 (1.8%) for ADHD hyperactive–impulsive type, and 102 (1.4%) for ADHD inattentive type with a male predominance. Binary logistic regression analysis showed that those with symptoms of ADHD (combined type) compared with the non-ADHD group had poorer academic performance, significantly higher substance use, psychological distress, suicidality, and sexual abuse. Conclusion: The high prevalence of self-reported ADHD symptoms and its association with negative correlates previously reported in literature in those with a diagnosis of ADHD suggests that clinically significant self-reported ADHD symptoms could be as disabling as ADHD.