Compulsive hoarding is a debilitating, chronic disorder, yet we know little about its onset, clinical features, or course throughout the life span. Hoarding symptoms often come to clinical attention when patients are in late life, and case reports of elderly hoarders abound. Yet no prior study has examined whether elderly compulsive hoarders have early or late onset of hoarding symptoms, whether their hoarding symptoms are idiopathic or secondary to other conditions, or whether their symptoms are similar to compulsive hoarding symptoms seen in younger and middle-aged populations. The objectives of this study were to determine the onset and illustrate the course and clinical features of late life compulsive hoarding, including psychiatric and medical comorbidities.