Abstract Fully edentulous patient with flabby ridge are a common case in clinic, but it is still challenging for the dentist to fabricate the denture. Flabby ridge is a fibrous tissue with soft consistency that can deform under large force and result in the patient's denture unstable. In cases of flabby ridge, the window, one step double spacer, and dual tray impression techniques are advised since they affect stress distribution and denture displacement. Dentist should pay close attention to impression technique in cases of flabby ridge because they have a significant impact on the fabrication of complete denture for effective stabilization. This study aimed to analyse the stress distribution and displacement in complete denture’s patient with flabby ridge used several impression techniques and applied mastication forces using Finite Element Analysis. Fabrication of three maxillary complete dentures from one fully edentulous patient with flabby ridges used three different impression techniques: window, one step double spacer and dual tray. Then, complete denture was scanned and replicated in software. Loads of 100 N axially and 119 N obliquely were then applied to simulate fully edentulous patient’s maximum bite force. Von Mises stress value on alveolar ridge mucosa and denture displacement were observed in complete dentures. The lowest von mises stress and displacement values were observed in complete denture with window impression technique followed by dual tray impression technique and one step double spacer technique so the window impression technique is the most ideal impression method to fabricate denture for patient with flabby ridge.