The aim of this systematic review was to evaluate the outcomes of flapless surgery for implants placed using either free-hand or guided (with or without 3D navigation) surgical methods. Literature searches were conducted to collect information on survival rate, marginal bone loss, and complications of implants placed with such surgeries. Twenty-three clinical studies with a minimum of 1 year follow-up time were finally selected and reviewed. Free-hand flapless surgery demonstrated survival rates between 98.3% and 100% and mean marginal bone loss between 0.09 and 1.40 mm at 1–4 years after implant insertion. Flapless guided surgery without 3D navigation showed survival rates between 91% and 100% and mean marginal bone loss of 0.89 mm after an observation period of 2–10 years. The survival rates and mean marginal bone loss for implants placed with 3D guided flapless surgery were 89–100% and 0.55–2.6 mm, respectively, at 1–5 years after implant insertion. In 17 studies, surgical and technical complications such as bone perforation, fracture of the surgical guide, and fracture of the provisional prosthesis were reported. However, none of the identified methods has demonstrated advantages over the others. Further studies are needed to confirm the predictability and effectiveness of 3D navigation techniques.