Complete denture is often used by patients that have edentulism. However, a long-term denture wearers commonly showed the hyperplastic growth of tissue called hyperplasia. This condition will present some difficulties for impression and retention. A 77 year old male patient reported to the RSGM UMY with a loose-fitting denture. He has been using it for 10 years. His old denture has suction cup on the palatal which no longer retentive and stable. The clinical examination showed the maxillary and mandibular complete edentulous ridge with flabby ridge area in the maxillary and mandibular anterior region. Patient is given treatment complete denture with acrylic resin material. In this case, window technique is used as the impression technique for a flabby ridge. Denture-induced hyperplasia is a condition of enlarged of fibrous tissue that could leads to poor denture retention, support, and stability. In the presence of hyperplasia, fabrication of as stable denture can be very arduous challenge. Special impression technique, like window technique frequently used on a case with flabby ridge. Window technique is a technique which use medium body impression material for the un-displaceable tissue whereas the flabby tissue impressed by using light body elastomer impression that must be freed from pressure. In patient with flabby ridge or hyperplasia due to denture, fabrication of impression need special technique like window technique which can be proven to ensure a final impression of the flabby ridge to improve denture stability, retention, support, and patient comfort.