Severe hypertriglyceridaemia is a rare presentation usually associated with acute pancreatitis. We present two case reports of severe hypertriglyceridaemia occurring in patients with previous autoimmune disease and haematological and solid malignancies but no evidence of prior or concurrent pancreatitis or hyperlipidaemia. These case reports illustrate that haematological and solid organ malignancies and autoimmunity may be relevant as exacerbating factors in the presentation of severe type IV or V hypertriglyceridaemia.