Salmonella mycotic aneurysm is a rare but potentially fatal condition. Mortality is high without timely intervention. The clinical presentation is protean and early diagnosis requires a high degree of clinical alertness. Prompt surgical intervention and prolonged antimicrobial therapy are keys to successful treatment. We report an 81-year-old man with an atypical presentation of Salmonella mycotic aneurysm in the aortic arch. The case highlights the need to evaluate all patients over 50 years with non-typhoid Salmonella bacteraemia for possible endovascular infections. Contrast-enhanced computed tomography is useful for making an early diagnosis of this disease.