Musculoskeletal disorders (MDs) represent a global health issue, which can lead to disability. Physical activity (PA) reduces pain and increases physical function among patients with MDs. To promote behavioural changes, it seems important to focus on modifiable factors, such as motivation. Thus, this review aims to assess effects of interventions targeting PA on motivation towards PA. Searches used terms referring to “physical activity”, “motivation” and “chronic musculoskeletal disorders” on the databases PubMed, PsychINFO, MEDLINE, EMBASE, PEDro and Web of Science. All types of intervention—including but not limited to RCTs—were eligible for inclusion. Risk of bias was assessed with the Quality Assessment Tool for Studies with Diverse Designs (QATSDD). Among 6 489 abstracts identified, there were 387 eligible studies and 19 were included, reporting in total 34 effect sizes. The meta-analysis concerned 1 869 patients and indicated a small effect of interventions on change in motivation towards PA (d = 0.34; 95% CI [0.15; 0.54]; p < .01; k = 33). Behavioural interventions positively impact PA motivation in patients with MDs. In the literature, most studies focused on intervention’s effect on fear of movement. Future research should assess other explicit motivational constructs, as well as implicit processes.