The present case study describes a cognitive-behavioral intervention directed at helping a 53 year old female suffering from compulsive hoarding decrease clutter and improve decision-making and sorting techniques. The intervention focused on decision-making training, exposure and response prevention, and cognitive restructuring. Ratios of cluttered space to overall space were calculated for floor and furniture tops for each of five rooms over a period of 17 months. Clutter decreased substantially in each of the rooms targeted for intervention, while clutter ratios remained stable for a room used as a baseline control (no intervention). In addition, D.'s scores on self-report measures of obsessive-compulsive symptomatology decreased after 9 months of intervention suggesting that the treatment protocol affected symptoms of hoarding distress, as well as clutter. Despite previously reported difficulties in the treatment of compulsive hoarding, our results provide preliminary evidence that a cognitive-behavioral intervention can be successful in reducing hoarding symptoms. Suggestions for future research include streamlining the treatment program and testing its efficacy on large clinical samples.