One of the goals that the prosthodontist has to achieve is to construct retentive and stable denture that subsequently enhances both function and esthetics (2). Subjective and objective contemplate provide controversial results of denture liners’ influence on the masticatory ability. While results of some considerations indicated that chewing efficiency remarkably improves the chewing ability. (3)Flexible acrylic resin liners offer better denture adaptation, patient satisfaction as well as denture retention due to its light weight and engaging more desirable undercuts (4). Aim of this study was toassess the flexible lining acrylic resin material’s influence on the chewing efficiency and activity of masticatory muscles in complete denture wearers. Materials and methods: Twenty six completely edentulous patients were selected and were divided into two groups, Group I: patients wearing conventional heat cured acrylic complete denture. Group II: patients wearing conventional heat cured acrylic complete denture relined by soft acrylic versacryl. Chewing efficiency and Electromyography records taken for both groups at time of insertion, after first, second and third month. Results: time taken during swallowing was decreased for patients wearing complete dentures lined with soft acrylic versacryl than conventional complete dentures. EMG activity for both the masseter and temporalis muscles were increased after the relining the complete denture with soft liner (versacryl). However, EMG activity of the masseter muscle was higher than the temporalis muscle in both groups.