Performance on the Spatial Span subtest of the Wechsler Memory Scale has been viewed as an indicator of working memory and visuospatial processing. A number of factors including age and gender have been posited to effect performance on Spatial Span by older adults. The current study examined the impact of various forms of cognitive impairment and severity of impairment on Spatial Span performance. Five hundred thirty-eight individuals between the ages of 65 and 89 were evaluated in a university memory disorders clinic using a battery of neuropsychological tests that included Spatial Span. Participants were grouped by consensus diagnosis into type of cognitive impairment (Alzheimer's disease, vascular disease, amnestic mild cognitive impairment or non-amnestic mild cognitive impairment) or cognitively normal. As expected, an increase in severity of impairment results in a decrease in Spatial Span Total Score. Other findings included a weak relationship between age and Spatial Span Total Score. Gender, as well as age, did not fully account for the decline in Spatial Span Total Score. Spatial Span Forward score was not as good a predictor of severity in that reduction in score for Spatial Span Forward remains relatively stable regardless of level of impairment. Spatial Span Backward performance was found to be more sensitive to severity. No significant differences were found between performance of Alzheimer's disease and vascular disease suggesting they share similar deficit patterns with regard to the cognitive abilities measured by the Spatial Span subtest. A comparison between those diagnosed with mild cognitive impairment and individuals without such a diagnosis showed no significant difference suggesting that visuospatial processes are not affected early in the dementing process.