While the Hamilton Rating Scale for Depression (HRSD) has been the standard instrument for the assessment of the severity of depression for many years, this scale has a number of limitations. We developed the Modified Hamilton Rating Scale for Depression (MHRSD) to overcome some of these limitations and to enable paraprofessional research assistants to make reliable and valid assessments of depressive symptoms. The present study investigates the reliability and validity of the MHRSD. Interrater reliability among paraprofessional research assistants was excellent. The relationship between the MHRSD and expert clinician ratings on the MHRSD and the original HRSD was also high. Thus, the MHRSD appears to be a useful addition to the clinical researcher's assessment battery.