Traditionally, hoarding symptoms were coded under obsessive-compulsive disorder (OCD), however, in DSM-5 hoarding symptoms are classified as a new independent diagnosis, hoarding disorder (HD). This change will likely have a considerable impact on the self-report scales that assess symptoms of OCD, since these scales often include items measuring symptoms of hoarding. This study evaluated the psychometric properties of one of the most commonly used self-report measures of OCD symptoms, the Obsessive-Compulsive Inventory-Revised (OCI-R), in a sample of 474 individuals with either OCD (n = 118), HD (n = 201), or no current or past psychiatric disorders (n = 155). Participants with HD were diagnosed according to the proposed DSM-5 criteria. For the purposes of this study the OCI-R was divided into two scales: the OCI-OCD (measuring the five dimensions of OCD) and the OCI-HD (measuring the hoarding dimension). Evidence of validity for the OCI-OCD and OCI-HD was obtained by comparing scores with the Saving Inventory Revised (SI-R), the Hoarding Rating Scale (HRS) and the Beck Anxiety Inventory (BAI). Receiver operating curves for both subscales indicated good sensitivity and specificity for cut-scores determining diagnostic status. The results indicated that the OCI-OCD and OCI-HD subscales are reliable and valid measures that adequately differentiate between DSM-5 diagnostic groups. Implications for the future use of the OCI-R in OCD and HD samples are discussed.