BACKGROUND: Recent research recommends physical exercise rather than rest following a mild traumatic brain injury (mTBI). OBJECTIVE: To determine the effect of physical exercise on persistent symptoms in people with mTBI. METHODS: A search of randomized controlled trials was conducted in CINAHL, Cochrane Library, EMBASE, MEDLINE, SportDiscus and Web of Science, from 2010 to January 2021. Studies were included if they described the effects of a physical exercise intervention in people with mTBI on persistent symptoms. Study quality, intervention reporting, and confidence in review findings were assessed with the CASP, TIDieR and GRADE respectively. RESULTS: 11 eligible studies were identified for inclusion. Study interventions broadly comprised of two categories of physical exercise, i.e., aerobic (n = 8) and vestibular (n = 3). A meta-analysis (n = 3) revealed the aerobic exercise group improvement was significantly larger compared to the usual care group –0.39 (95% CI: –0.73 to –0.05, p = 0.03). Only three studies using vestibular exercise reported on persistent symptoms and yielded mixed results. CONCLUSIONS: This study demonstrated that the use of aerobic exercise is supported by mixed quality evidence and moderate certainty of evidence, yet there is limited evidence for the use of vestibular exercise for improving persistent symptoms in people with mTBI.