We aimed to determine whether voice rehabilitation after radiotherapy improves the quality of life (QOL), voice function, and self-rated voice function in patients with laryngeal cancer. We searched CENTRAL, MEDLINE, EMBASE, PEDro, and World Health Organization International Clinical Trials Registry Platform for randomized controlled trials published between inception and October 2018. The primary outcome was QOL, adverse events and mortality. Secondary outcomes included voice function and self-rated voice function. The quality of evidence was determined using the Grading of Recommendations Assessment, Development, and Evaluation approach. Three trials (enrolling 122 patients) compared voice rehabilitation to usual care or no intervention after radiotherapy. Voice rehabilitation did not significantly improve any QOL scores. Data on adverse events and mortality were not available in any of the trials. Voice rehabilitation did not improve any voice function scores, such as jitter (mean difference: - 0.48 [- 1.27 to 0.32]), shimmer (mean difference: - 0.04 [- 0.27 to 0.19]), maximum phonation time (mean difference: 1.54 [- 1.13 to 4.22]), and the grade, roughness, breathiness, asthenia, and strain scale (mean difference: - 0.39 [- 2.59 to 1.80]). Voice rehabilitation also did not improve the voice handicap index, which was used as a self-rated voice function score (mean difference: 5.54 [- 2.07 to 13.16]). The certainty of the evidence was graded as low for primary and secondary outcomes. Voice rehabilitation for patients with laryngeal cancer after radiotherapy might not improve QOL, voice function, and self-rated voice function. Pre-specified voice rehabilitation programs may not be necessary for all patients with laryngeal cancer after radiotherapy.