OBJECTIVE: This study aims to establish the effect of electromagnetic diathermy therapies (e.g., shortwave, microwave, capacitive resistive electric transfer) on pain, function, and quality of life in treating musculoskeletal disorders. METHODS: We conducted a systematic review according to the PRISMA statement and Cochrane Handbook 6.3. The protocol has been registered in PROSPERO: CRD42021239466. The search was conducted in PubMed, PEDro, CENTRAL, EMBASE, and CINAHL. RESULTS: We retrieved 13,323 records; 68 studies were included. Many pathologies were treated with diathermy against placebo, as a standalone intervention or alongside other therapies. Most of the pooled studies did not show significant improvements in the primary outcomes. While the analysis of single studies shows several significant results in favour of diathermy, all comparisons considered had a GRADE quality of evidence between low and very low. CONCLUSIONS: The included studies show controversial results. Most of the pooled studies present very low quality of evidence and no significant results, while single studies have significant results with a slightly higher quality of evidence (low), highlighting a critical lack of evidence in the field. The results did not support the adoption of diathermy in a clinical context, preferring therapies supported by evidence.