Neurofibromatosis-1 (NF-1) is an autosomal dominant condition characterized by cutaneous pigmentation and tumour formation along nerves in the brain, skin, and other organs. Gastrointestinal stromal tumours (GIST) are rare mesenchymal tumours involving the gastrointestinal tract (GI) associated with NF-1. We present a case of life-threatening GI bleeding from GIST in a patient with NF-1. In NF-1 patients presenting with GI bleeding, GISTs should be part of the differential. Clinicians must have a low threshold for urgent abdominal imaging if endoscopy does not detect the source of GI bleeding.