Diogenes syndrome (DS) is a behavioral disorder characterized by personal and social neglect. It has been described mostly in the elderly. People suffering from this syndrome accumulate large amounts of rubbish and useless objects, and live in poverty although they have the means to avoid it. They have also avoidance behavior, social withdrawal and anosognosia. Investigation on this syndrome has been sparse, and even its value as a clinical diagnosis has been questioned. Between one half and two-thirds of those who have it suffer from dementia or some type of psychiatric disorder. We describe a patient with DS as a clinical manifestation of frontotemporal dementia, and detail his clinical picture and course.