This study aimed to evaluate the clinical outcomes of patients with acute heart failure (AHF) stratified by mitral regurgitation (MR) in the Arabian Gulf. Patients from the Gulf CARE registry were identified from 47 hospitals in seven Arabian Gulf countries (Yemen, Oman, Kuwait, Qatar, Bahrain, the United Arab Emirates, and Saudi Arabia) from February to November 2012. The cohort was stratified into two groups based on the presence of MR. Univariable and multivariable statistical analyses were performed. The population cohort included 5005 consecutive patients presenting with AHF, of whom 1491 (29.8 %) had concomitant MR. The mean age of patients with AHF and concomitant MR was 59.2 ± 14.9 years, and 63.1 % (n = 2886) were male. A total of 58.6 % (n = 2683) had heart failure (HF) with reduced ejection fraction (EF) (HFrEF), 21.0 % (n = 961) had HF with mildly reduced EF (HFmrEF), and 20.4 % (n = 932) had HF with preserved EF (HFpEF). Patients with MR had a lower haemoglobin (Hb) level (12.4 vs. 12.7 g/dL; p