OBJECTIVES: This research aims to review and summarize the most recent data on the epidemiology of patients with B-cell R/R aALL globally, with particular focus on the US, Canada and EU5. METHODS: In April 2020, we conducted a SLR to identify the incidence, prevalence, and mortality of R/R aALL in Medline and EMBASE (2015-2020) combined with desk research (no time limit) of publicly available databases, appraisals and registries. RESULTS: In total, 16 journal articles and 16 other sources were identified. Data for R/R aALL were mostly identified regardless of treatment line, B-cell disease and age subgroups. Incidence rate per 100,000 was 0.25 (117/46M) for B-cell R/R aALL in the UK (n=1). For countries without published incidence, the rate per 100,000 was calculated assuming 48% of ALL patients were relapsed or refractory (based on published trial results included in a UK appraisal): 0.26–0.82 in the US (n=2), 0.22–0.67 in Canada (n=2), 0.26 in Germany (n=1), 0.23 in France (n=1), 0.35 in Italy (n=1), 0.26 in Spain (n=1), and 0.22-0.24 in Netherlands (n=2). The calculated prevalence ranged from 3.00 (US) to 11.21 (Italy). Country-specific survival in patients with R/R aALL was reported for the UK (n=2): 5-yrs survival <10%^,; Germany (n=1): 3-yrs survival 24%; and the US (n=1): 1-yr survival 13-19%. CONCLUSIONS: Although limited data were found, incidence for R/R aALL seems comparable across countries. Prevalence and survival of R/R aALL vary substantially between countries. Current treatments are associated with poor survival and better treatment options are needed to improve outcomes.