This research aimed to test the validity and reliability of the ‘World Health Organization Mental Disorders Checklist’ for use in a telehealth clinic in Hong Kong. The Checklist adopted four subscales: (i) depression; (ii) anxiety; (iii) alcohol use disorders; and (vi) functioning and disablement, and was translated from English into Chinese. It was validated by a panel of five experts to confirm its content validity (content validity index = 0.98) and cultural appropriateness in Hong Kong. The reliability of the checklist was supported by the findings of a test–retest procedure (Pearson correlation = 0.66–0.88, P < 0.01), internal consistency reliability (Cronbach's alpha = 0.54–0.83), and interrater reliability (Kendall's coefficient of concordance = 0.58–1.00, P < 0.01) involving a sample of 197 subjects from one telehealth clinic in Hong Kong.