The rise in internet addiction, including web-based gaming and social networking services, is a serious concern. Even with access to medical institutions and counseling services, individuals with internet addiction, particularly adolescents, often refuse medical treatment or counseling. Parent-focused psychological intervention may lead to positive outcomes by improving the parent-adolescent relationship and helping parents identify and modify their adolescent's problematic behaviors, including internet addiction. This study was a pilot randomized controlled trial to test the feasibility of remote cognitive behavioral therapy via videoconferencing for parents of adolescents with internet addiction. A total of 13 parents of adolescents aged 12-20 years with internet addiction were recruited and randomly assigned to either 12 sessions of the videoconference-delivered cognitive behavioral therapy (vCBT) group (n=6, 46%) or the waitlist control group (n=7, 54%). The study period was from March 1, 2018, to March 31, 2022. The primary outcome was the scores of the Young Internet Addiction Test reported by the adolescents. The secondary outcomes were adolescents' hours of internet use per day (Internet Addiction Test), reported by the adolescents and by their parents; the Young Diagnostic Questionnaire, completed by the parents; and the quality of life of the adolescents and the parents, measured by the EQ-5D-5L. These were evaluated at weeks 0 and 13. As the primary outcome, the mean total Internet Addiction Test score decreased from 67.7 (SD 18.3; 6/13, 46%) at week 0 to 56.2 (SD 25.1; 5/9, 56%) at week 13 in the vCBT group, compared to an increase from 66.9 (SD 21.9; 7/13, 54%) to 68.0 (SD 18.7; 4/9, 44%) in the control group. For all outcomes, no significant differences were found between the 2 groups (all P>.05). This study suggested the practical feasibility of vCBT for parents of adolescents with internet addiction. Further large-scale, multicenter randomized controlled trials are necessary to examine the effectiveness. UMIN Clinical Trials Registry UMIN000032483; https://tinyurl.com/yuhen6c9.