Background/Aims: To examine characteristics, including mental health comorbidities, among adolescents presenting to a transgender clinic and to compare these data to previous reports. Methods: Retrospective chart review among youth seen at The Hospital for Sick Children between January 2014 and June 2016. Demographic data, clinical characteristics, and mental health comorbidities were assessed. Baseline and repeat blood work were also examined. Results: Charts from 203 adolescents aged 12–18 years were reviewed (156 assigned female at birth [AFAB] (77%) aged 16.3 ± 1.63 years, 47 assigned male at birth [AMAB] aged 16.1 ± 1.70 years). There was no statistically significant difference between gender groups except for Tanner stage (AFAB, mean 4.42 ± 0.8 and AMAB, mean 4.03 ± 1.1, p = 0.040). Individuals from racial/ethnic minority populations were under-represented compared to the background population. Self-report and baseline psychological questionnaires showed high levels of gender dysphoria, mood disorders, and suicidal ideation, with higher levels of anxiety detected on questionnaires among AFAB (p = 0.03). Laboratory abnormalities identified on baseline and repeat testing were minor; on cross-sex hormones, hemoglobin levels increased slightly in AFAB (p = 0.002, highest = 166 g/L) and decreased among AMAB (p = 0.02, lowest = 132 g/L). Conclusion: Our study supports an evolving demographic trend with more AFAB than AMAB youth now presenting to gender clinics. The data also corroborate studies indicating that extensive laboratory testing may not be a necessary part of caring for these youths. Why more AFAB are now presenting to clinic and racial/ethnic minorities are underrepresented is not clear, but these trends have important implications for clinical care and warrant further study.