Implant secondary surgery is an operation that exposes the implant fixture into the oral cavity. Depending on the surgical procedure, keratinized gingiva surrounding the implant may be affected, that may affect long-term prognosis of the implant. The purpose of this case report is to introduce a minimally invasive 2nd stage surgery and to evaluate its clinical features and effect on preservation of keratinized gingiva. Minimally invasive 2nd stage surgery was performed in three patients that had completed first stage implant surgery. The width of keratinized gingiva was measured immediately after surgery and after completion of prosthesis. As a result, the width of keratinized gingiva was preserved, patient's discomfort was reduced, and the operation duration was shortened.