Definition of Walkthrough. The final inspection of a home by the buyers before it's sold. Buyers will complete a final walkthrough of the home to make sure any requests for repairs or appliances have been fulfilled before the closing papers are signed. A walkthrough happens anywhere from a few days to a few hours before closing. If something isn't right, the buyers should ask the sellers to fix the problem before the sale is final. In some regions, a final walkthrough is not a guaranteed step, and it must be written into the purchase and sale agreement.