Overweight patients with cancer are frequently reduced in chemotherapy dose due to toxicity concerns, although previous studies have indicated that dose reduction (DR) of overweight patients results in comparable toxicity but may compromise overall survival (OS). Current evidence regarding DR in patients with acute myeloid leukaemia (AML) is limited. To investigate the association between DR and outcome among overweight patients with AML we analysed a Danish nationwide cohort of overweight adult AML patients treated with remission induction chemotherapy. Among 536 patients identified, 10.1% were categorized as DR defined as 95% or less of full body surface area (BSA)-based dose. Risk factors for DR were high body mass index (BMI) and BSA, therapy-related AML and favourable cytogenetics. No significant differences were observed for rates of complete remission (CR), 30- and 90-day mortality between DR and non-DR patients. Furthermore, DR did not affect median relapse-free survival (RFS) [DR, 14.5 (95% confidence interval, 9.0-41.7) months; non-DR, 15.0 (12.3-19.3)] with an adjusted difference in five-year restricted mean survival time (Δ5y-RMST) of 0.2 (-8.4 to 8.8) months nor median OS (DR, 17.0 [11.9 to 45.5] months; non-DR, 17.5 [14.8 to 20.5]) with an adjusted Δ5y-RMST of 0.8 (-5.7 to 7.3) months. In conclusion, we found no statistically significant association between DR and outcomes among overweight patients with AML. However, we acknowledge the limited sample size and encourage further studies in this important subject.