Introduction: Acutely decompensated heart failure (ADHF) usually results in hospitalisation for intravenous diuretics. The safety and efficacy of ambulatory or outpatient management of ADHF by heart failure specialist nurses has not been described before. Methods: This retrospective analysis compared 2 cohorts of consecutive ADHF patients - hospitalised in-patients (IP) versus outpatients (OP) who were treated with bolus intravenous diuretics in a specialist heart failure nurse delivered consultant led OP HF unit (Ambulatory HF Unit -AHFU) with input from various specialties (renal, diabetes, elderly care, chest, pharmacy, palliative, ascitic, pleural teams) from 2016 to 2020. Mean follow-up duration was similar for both groups (IP=46±8.1 months; OP=45.5± 7 months, p=0.1). We compared clinical risk scores using the Get With the Guidelines (GWTG) score, comorbidities using the Charlson Comorbidity Index (CCI) and frailty using the Rockwood Clinical Frailty Index (CFI). Results were expressed as mean±SD, analysed using the Student’s T test and Chi-squared test. Results: 1012 patients were treated in our specialist outpatient AHFU and 1889 patients were hospitalised. Mean number of visits per ambulatory spell was 5.1±-2.2 days and the median dose of furosemide was 220 mg (range 80-480). Average hospital stay for IP was 12.1±5 days. CCI (IP=6.5±2; OP=6.4±1.9; p=0.19) and mean GWTG scores were similar (IP=40.4±7.9; OP=39.9±7.1; p=0.09) between the 2 groups but mean Frailty Index was higher amongst the IP group (IP 5.1±1.2; OP 4.9±1; p=0<0.001). 30 day hospitalisation and mortality (30 day,1 year and overall mortality) were lower in the OP cohorts. Conclusions: Ambulatory management of ADHF using bolus IV diuretics in a heart failure specialist nurse delivered consultant led multidisciplinary unit offers an effective alternative to hospitalisation and also leads to improved outcomes. Frailty Index can help assess suitability for outpatient management of ADHF.