This chapter, written for undergraduate medical students and post-graduate doctors in training, presents information on how to manage brown tongue — a case which they are likely to encounter in the future in a general practice setting. It presents the case of a 58-year-old woman who comes to the surgery complaining that her tongue has gone brown, her mouth has been feeling dry and she has been experiencing a bad taste. The chapter provides details of the patients' medical history and the key findings of clinical examination, together with initial investigation results data for evaluation, and helps them develop their skills of clinical reasoning. The patient is well-known to the surgery. She has a medical history of depression and attends regularly with chest infections. She suffers from chronic obstructive pulmonary disease (COPD) after 40 pack-years of smoking. Key questions then prompt the student to evaluate the patient, and reach a decision regarding their condition and the possible treatment plan.