Purpose: To investigate the effect of physical exercise on body structure & function and activity outcomes in individuals with Mild Cognitive Impairment (MCI). Methods: Six databases were searched from inception until January 2021. Randomized controlled trials (RCTs) comparing physical exercise with a control group were included. Results: Fourteen RCTs were included. Three types of physical exercise were identified: aerobic (AE), resistance (RE), and multimodal (ME). Regarding body structure & function outcomes, evidence for RE was very low and with effect for improvement in upper limb muscle strength and very low and without effect for lower limbs. For improvement in postural balance, evidence was very low and with effect with AE and very low and without effect with RE and ME. Evidence for cardiorespiratory function was very low and without effect with AE and RE. Regarding activity outcomes, evidence was low and without effect for mobility with AE and very low and without effect with RE and ME. Conclusions: Physical exercise promoted improvements in body structure & function outcomes in individuals with MCI. Resistance exercise improvement upper limb muscle strength and AE enhanced postural balance. In contrast, physical exercise did not promote a significant benefit in activity outcomes.Implications for rehabilitationResults of this systematic review have shown that physical exercise promoted improvements in body structure & function outcomes in individuals with Mild Cognitive Impairment (MCI).Resistance exercise with elastic bands for approximately 60 minutes twice a week for a total of three months improved upper limb muscle strength.Aerobic exercise with walking for approximately 60 minutes twice per week for a total of six months enhanced postural balance.Considering the potential benefits identified in this systematic review, physical exercise can be recommended for individuals with MCI.We also highlight the importance of the use of the International Classification of Functioning, Disability and Health for rehabilitation planning.