Background Little is known about the DSM‐IV diagnosis of insomnia among adolescents. Their help‐seeking behaviors and self‐help strategies for insomnia remain largely unclear. Method A cross‐sectional, interview‐based study of 290 Chinese adolescents. Results The prevalence of insomnia symptoms was 40%, among which 9.3% had DSM‐IV insomnia. Primary insomnia accounted for 7.9%, whereas insomnia associated with psychiatric disorders constituted 1.4%. Adolescents with DSM‐IV insomnia had more severe and frequent insomnia, higher GHQ scores, and were more likely to have a history of sleep paralysis than those with insomnia symptoms alone. About 22% of adolescents with insomnia symptoms sought help and 32% attempted various strategies to improve sleep. Conclusions Many adolescents were troubled by insomnia, but they seldom sought help from healthcare professionals or received proper treatments.