Background: Alemtuzumab is a humanized anti-CD 52 monoclonal antibody approved as a disease-modifying therapy for active relapsing-remitting Multiple Sclerosis (MS). Alemtuzumab has been associated with several adverse effects, including infusion-associated reactions, infections, acquired autoimmune diseases, and malignancies. Case presentation: We report a case of Alemtuzumab-induced simultaneous onset of autoimmune haemolytic anaemia, alveolar haemorrhage, nephropathy and stroke in a 52-year-old man that occurred 8 months after initiation of alemtuzumab. The laboratory testing was consistent with autoimmune haemolytic anaemia. Computed tomography of the chest and bronchoscopy revealed an alveolar haemorrhage. Stroke workup revealed acute infarcts in bilateral occipital territories. Conclusion: This is the first case report of a simultaneous onset of autoimmune haemolytic anaemia, alveolar haemorrhage, nephropathy, and ischaemic stroke after the first alemtuzumab course in relapsing-remitting MS patient. This case highlights the potential for the co-occurrence of unexpected and potentially life-threatening complications of alemtuzumab therapy necessitating rigorous monitoring once prescribed.