This study examined the relation between sleep quality and cognitive performance in older adults, controlling for common medical comorbidities. Participants were community volunteers who, while not selected on the basis of their sleep, did report substantial variability in sleep quality. Good and poor sleepers differed on tests of working memory, attentional set shifting, and abstract problem solving but not on processing speed, inhibitory function, or episodic memory. Poor sleep was also associated with increased depressive symptomatology but only for functional symptoms (e.g., decreased concentration) and not for mood (e.g., sadness). The relationships between sleep quality and cognition were not explained by confound factors such as cerebrovascular disease, depression, or medication usage. Sleep problems may contribute to performance variability between elderly individuals but only in certain cognitive domains.