Ninety-six subjects in three age groups (50-59,60-69,70-79) who resided at home were tested on their appreciation and comprehension of 12 conservation and 12 nonconservation jokes. The conservation jokes depended on the piagetian concepts of conservation of mass, weight, and volume for their comprehension. Cognitive ability of the subjects on the three conservation tasks was also tested. Appreciation increased with age and comprehension decreased with age for both types of jokes. The ability to conserve volume declined with age. Among conservers of volume, appreciation of conservation of volume jokes increased with age; among nonconservers, it tended to decrease. The study provided some support to the hypothesis that the cognitive perceptual theory of humor applies in old age as it does in childhood, with appreciation depending on a match between ability level and the cognitive demand of the joke.