The goal of this study was to understand factors related to humor comprehension in old age. This study proposes that, in contrast to younger adults, older adults have greater difficulty with humor comprehension due to age-related cognitive decline. Tests of verbal and nonverbal humor comprehension and tests of cognitive flexibility, abstract reasoning, and short-term memory were administered to 40 younger and 41 older adults. In general, older adults scored lower than younger adults on tests of humor and cognitive abilities. Regression analyses support the idea that cognition affects humor comprehension, but the relative contribution of each specific mechanism remains unclear. The results of this study suggest that there may be age-related deficits in humor comprehension, but more importantly, that a more sophisticated model is needed to clarify the role of cognition in humor comprehension. Humor comprehension warrants further study because of the potential physical and psychological benefits of humor. (JINS, 2007, 13, 606–614.)