Clinical guidelines recommend that all patients with diabetes should be screened annually to establish their risk of foot ulceration. The aim of this systematic review was to quantify the predictive value of diagnostic tests, physical signs and elements from the patient's history in relation to diabetic foot ulcers. Observational studies were identified from: electronic databases (MEDLINE, EMBASE and CINAHL); bibliographies of studies meeting the inclusion criteria; review articles and clinical guidelines; direct contact with authors. Published reports of cohort and case-control studies were considered for inclusion. Pooled estimates were calculated from absolute numbers as weighted mean differences, standard mean differences or odds ratios. Adjusted odds ratios from published reports were also extracted. We identified five case-control and 11 cohort studies. The incidence of foot ulcers ranged from 8% to 17% in the cohort studies, with varying lengths of follow-up. Diagnostic tests and physical signs that detect peripheral neuropathy (biothesiometry, monofilaments and absent ankle reflexes), and those that detect excessive plantar pressure (peak plantar pressure and joint deformity) were all significantly associated with future diabetic foot ulceration. However, there was a paucity of evidence concerning the predictive value of symptoms and signs. Further research is needed to establish the independent factors associated with diabetic foot ulceration, particularly elements from a patient's history and physical examination.