Introduction Understanding the effects of periodontal therapy is essential in performance and satisfaction of partially dentate patients. Objective To assess the effect of subgingival periodontal treatment in performance and masticatory satisfaction and ability as reported by partially dentate patients with untreated chronic periodontitis. Materials and method Patients were given nonsurgical periodontal treatment and masticatory satisfaction, ability, and performance were evaluated before and after treatment. Performance was assessed based on sieving chewed standardized chewable material, while satisfaction and ability were analyzed using a questionnaire based on OHIP-EDENT. Result Mean numbers of functional tooth units were 10.36 ± 1.43 anterior and 6.73 ± 0.79 posterior teeth. Masticatory performance did not vary significantly (p = 0.075), and mean particle sizes before and after treatment were 4.23 ± 1.84 mm and 3.90 ± 0.75 mm, respectively. Overall satisfaction and ability scores after treatment were higher (p > 0.05) compared with scores prior to the periodontal intervention. Conclusion Periodontal treatment improves masticatory satisfaction and ability with no effect on performance.