Background: To date, autologous punch grafting appears to be the easiest and least expensive surgical technique for stable vitiligo and piebaldism. Punch grafting is available worldwide, with no need for specialised instruments. However, no reliable data on efficacy and safety of different punch depths and punch sizes are available. Objective/methods: To compare the efficacy and safety of different punch depths and punch sizes in autologous punch grafting, a randomised controlled trial was performed in 33 patients with vitiligo or piebaldism. In each patient, four depigmented regions were allocated to: 1.5 mm deep grafts, 1.5 mm superficial grafts, 1.0 mm deep grafts, and 1.0 mm superficial grafts. Primary outcome was the total pigmented surface area. Secondary outcomes were Patients’ Global Assessment (PGA) and side effects. Results: Six months after grafting, 1.5 mm grafts showed a significantly larger pigmented surface area compared to 1.0-mm grafts (p < 0.001), though more side effects as well. No significant differences in the total pigmented surface between different punch depths were found. Deep grafts showed more erythema compared to superficial grafts. Conclusion: We recommend 1.5 mm superficial grafts in autologous punch grafting for trunk and proximal extremities in patients with stable vitiligo and piebaldism.