Purpose: In space, astronauts are subject to microgravity, which reduces skeletal loading and osteoblast function and can cause bone resorption and a decrease in bone density. No known research to date has studied the effect of microgravity on dental implants. This study evaluated peri-implant bone changes around a dental implant placed in a French astronaut who spent 6 months in Russia's Mir Space Station. Materials and Methods: Measurements were performed by 2 examiners before the flight (baseline), after the flight (stage 1), and following a recovery period (stage 2). Standardized periapical radiographs were taken, and data were recorded using a photomicroscope and a measuring scale. Results: Cumulatively, the implant sustained 0.43 mm of mesial bone gain and 0.31 mm of distal bone loss. Discussion: The observed peri-implant bone height changes were within normal limits and the implant appeared very stable during the course of this study. Conclusion: Peri-implant bone levels remained stable after 6 months in microgravity, and the implant continued to function without complications. (Case Report) Keywords: dental implants, microgravity, peri-implant bone, space flight