Hoarding is considered by many to be a symptom of obsessive-compulsive disorder (OCD). Yet although it is observed in people with OCD, hoarding symptoms also appear in a number of other psychological and psychiatric conditions. The present studies were conducted using samples of OCD patients, patients with other anxiety disorders, and a non-clinical sample to further elucidate the relationship between hoarding and OCD. Across two investigations, we found that (a) whereas OCD patients had higher scores than the other groups on non-hoarding symptoms, this was not the case for hoarding symptoms; (b) hoarding tended to correlate more weakly with other OCD symptoms (e.g., washing, checking) than these other symptoms intercorrelated; (c) items measuring hoarding had the weakest factor loadings when a measure of OCD symptoms was submitted to factor analysis; (d) hoarding symptoms were not correlated with global OCD or anxiety severity, whereas other OCD symptoms were; and (e) hoarding did not show consistent relationships with OCD-related cognitive variables. These results do not support a specific relationship between hoarding and OCD; and they call into question hoarding's status as a specific symptom of OCD. Results are also discussed in terms of the importance of functional assessment of hoarding and OCD symptoms.