To examine maternal influence and related variables on adolescents' decision to adopt Norplant. A prospective study of 121 adolescent females who received Norplant through a hospital-based outpatient adolescent gynecology service. Each patient completed self-report questionnaires about her decision process, sexual behaviors and standardized measures of depression and anxiety at their insertion appointment or first-follow-up appointment. Almost 40% of the sample reported that their mother significantly influenced their decision to use Norplant and 61% of all patients stated that they had informed their mother of their choice of this contraceptive method. Through logistic regression, six variables were found to be significantly associated with mother as the most important decision source. These included: obtaining information about Norplant from a parent, maintaining the same sexual partner, past pill use, and not knowing other adolescents who boast about using the Norplant system. These data suggest that when parental consent is not required, adolescent females disclose sensitive information regarding choice-making to their mothers when they decided to adopt Norplant.