Internet-based cognitive behavioural therapy (ICBT) has been recommended by the NICE guidelines as one of the low-intensity interventions for people with depression and anxiety. Mindwork is a randomised controlled trial funded by Health and Medical Research Fund. Mindwork aims to evaluate the efficacy of ICBT in treating working adults with depression and anxiety in Hong Kong at post-treatment and 6-month follow-up. We hypothesized that ICBT in Mindwork could better improve recovery rate and productivity than its active control group, which include greater reduction in absenteeism and presenteeism, and unperformed unpaid work. Focusing on repetitive negative thinking, and intolerance of uncertainty, Mindwork also adopted an transdiagnoistic approach in reducing depression and anxiety symptoms.