The primary aim of this systematic review was to investigate the relationship between body mass index (BMI) and foot disorders. The secondary aim was to investigate whether weight loss is effective for reducing foot pain. Five electronic databases (Ovid MEDLINE, Ovid EMBASE, Ovid AMED, CINAHL and The Cochrane Library) and reference lists from relevant papers were searched in April 2011. Twenty-five papers that reported on the association between BMI and musculoskeletal foot disorders met our inclusion criteria and were reviewed. The evidence indicates: (i) a strong association between increased BMI and non-specific foot pain; and (ii) a strong association between increased BMI and chronic plantar heel pain in a non-athletic population. The evidence is inconclusive regarding the relationship between BMI and the following specific disorders of the foot; hallux valgus, tendonitis, osteoarthritis and flat foot. With respect to our second aim, there were only two prospective cohort studies that reported a reduction in foot symptoms following weight loss surgery. In summary, increased BMI is strongly associated with non-specific foot pain in the general population and chronic plantar heel pain in a non-athletic population. However, there is currently limited evidence to support weight loss to reduce foot pain.