In the present study, we examined the relationships between ratings on the Global Deterioration Scale (GDS) and activities of daily living and cognitive function in 39 individuals with vascular dementia (VaD). The results of the study revealed significant correlations between GDS rating and performance on cognitive tests, including memory and overall cognitive ability. In addition, the GDS was significantly related to ratings of instrumental activities of daily living. Comparisons between patients with VaD with GDS scores between 4 and 6 (n = 21) and patients with scores between 2 and 3 (n = 18) revealed greater cognitive and functional deficits in the group with higher GDS scores. Further, the GDS score accurately classified 87% of the patients with VaD. These findings provide support for the validity of the GDS in general staging of dementia severity of VaD.