Purpose: Chronic prostatitis (CP)/chronic pelvic pain syndrome (CPPS) has been studied mainly in adults; reports in adolescents are rare. We compared the clinical characteristics of adolescent CP/CPPS patients with those of young adults. Materials and Methods: We retrospectively analyzed 20 adolescents with CP/CPPS aged < 20 years who visited our outpatient department from August 2005 to April 2012. The control group comprised 120 young adult CP/CPPS patients. A complete medical history, physical examination, the national institute of health-chronic prostatitis symptoms index (NIH-CPSI) questionnaire, urinalysis, expressed prostatic secretion (EPS) or semen analysis, transrectal prostate ultrasonography, and prostate-specific antigen (PSA) were performed. Based on the EPS or semen analysis, patients were divided into category III-A or III-B. Results: The mean age was 16.5 +/- 2.0 and 32.8 +/- 5.0 years in the adolescent and control groups, respectively. A sexual activity history was seen in 2 patients; 9 and 11 patients were in category III-A and III-B, respectively. The PSA was 0.65 +/- 0.39 and 1.22 +/- 0.48 ng/mL in the adolescent and control groups, respectively. The prostate size was 12.4 +/- 4.4 and 21.0 +/- 4.9 g in the adolescent and control groups, respectively. The NIH-CPSI scores in the adolescent group were 9.2 +/- 5.2, 5.5 +/- 3.5, 7.5 +/- 3.2, and 22.2 +/- 8.1 for pain, voiding, quality of life (QoL) domains, and total scores, respectively. The adolescent group showed a tendency to exhibit high voiding symptom scores. Conclusions: CPPS has an equally severe impact on QoL in adults and adolescents. Apart from high voiding symptom scores in adolescents, no difference was found in terms of urologic clinical parameters.