PURPOSE: To evaluate the effect of palatal augmentation prosthesis (PAP) in improving speech intelligibility, swallowing efficacy, masticatory function, patients' perception, and overall quality of life (QoL) in HNC survivors with partial or total glossectomy. METHODS: The systematic review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the International Prospective Register of Systematic Reviews (PROSPERO). The focused question was constructed according to the PICO (participant, intervention, comparison, and outcome) approach, and a three-stage screening in PubMed, Cochrane, Scopus, and Google Scholar databases with Medical Subject Heading (MeSH) terms was performed. The National Institute of Health (NIH) tool, "Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group," was employed for risk of bias assessment, and the data was synthesized qualitatively, according to the Synthesis without Meta-Analysis (SWiM) reporting guideline. RESULTS: The initial search resulted in 131 articles, 80 were screened based on title and abstract, 11 full text articles were assessed for eligibility, and 9 articles were evaluated. Eight studies (88.9%) were characterized as fair and one as good. The total sample size included 176 participants. The "before" assessment was performed post-operatively, before PAP insertion, and the "after" at a time point ranging from after PAP insertion to a mean time of 9.3 (10.6) months, with a follow-up period ranging from 2 weeks to 82 months (mean time of 13.7 (17.3) months). Speech intelligibility was evaluated in eight studies. Six studies assessed swallowing and deglutition. Lingual movement dynamics of the center of the tongue, mastication ability, and patients' reported experience with PAP were each evaluated in one study. QoL assessment was performed in two studies. The results of this systematic review indicate that PAP has a significant effect in improving speech intelligibility, swallowing efficacy, masticatory function, patients' perceived outcomes, and overall QoL in HNC survivors with partial or total glossectomy. CONCLUSION: Due to the particular defect site-related disabilities, patients with tongue resection could benefit from PAP prostheses. However, future studies evaluating the role of PAP in alleviating speech and swallowing by means of current methods of assessment, as well as more explicit patient's perceived treatment outcomes and QoL evaluations, are essential.