For an actual surgical procedure under sedation or general anesthesia, plan to be in Korea for at least 7 to 14 days. That window covers the two things you can't rush. First, you need the surgeon who placed your stitches to take them out. Second, you want the riskiest stretch of early swelling and clot formation to pass before you sit still on a plane for hours.
Injectables and light laser work are the exception, and those can be same-day. But anything involving incisions, bone, or general anesthesia is different. Cut the trip too short and you're either flying with stitches still in or paying to change a flight at the worst possible moment. The per-procedure table below is the heart of this guide. Read every number as a typical range, not a promise, and confirm your own timeline with your surgeon, because healing varies a lot from person to person.