Minocycline-induced nail pigmentation is an uncommon side-effect. It usually develops after years of the therapy, and coincides with other pigmented sites. We report a 73-year-old male and a 33-year-old female developing nail discoloration after 8 weeks of therapy of 100 mg minocycline twice daily. No other pigmentation was found elsewhere on the skin, mucous membranes, teeth or sclerae of them. Our cases demonstrate that nail pigmentation can occur after short-term minocycline therapy, and propose the possibility that nail discoloration may precede other pigmentary changes.