Objectives: (1) Determine the one-week prevalence of moderate to extreme symptoms of anxiety, stress and depression in chiropractic undergraduate students. (2) Determine whether the prevalence varies across gender and year of study. Participants: Undergraduate students at the Canadian Memorial Chiropractic College (CMCC). Methods: A cross-sectional study was conducted in fall 2017 to measure self-reported symptoms of anxiety, stress and depression using the DASS21. Results: The participation rate was 67.0% (510/766). The one-week prevalence of moderate to extreme symptoms was 19.0% (95% CI: 13.0-25.0) for depression; 32.6% (95% CI: 24.7-40.3) for anxiety and 21.8% (95% CI: 15.6-28.1) for stress. The prevalence of stress varied significantly across gender: 25.4% (95% CI: 20.5-30.3) for females versus 16.3% (95% CI: 11.2-21.3) for males. The one-week prevalence of depressive (24.8%; 95% CI: 17.6-32.0) and anxiety (40.9%; 95% CI: 32.6-49.1) symptoms peaked in second year. Conclusions: Self-reported symptoms of anxiety, stress and depression are common in CMCC students.