Numerous studies have highlighted the beneficial effect of humor on memory in younger adults. While older adults are known to preferentially process positive information and appreciate humor, no study has investigated whether the effect of humor on memory persists in aging. Two studies were conducted to address this gap. In Study 1, 19 younger adults and 20 older adults performed a memory task designed to compare the recall of humorous and neutral photograph sequences. Results revealed the typical beneficial effect of humor on free recall in young adults, while in older adults, humor had no influence on free recall and even a detrimental effect in the cued recall task, suggesting that humor primarily affects encoding processes. Study 2 aimed to replicate these findings and further investigate the mechanisms underlying this negative effect in older adults (i.e., the effect of humor per se or confounding incongruity effect). To this end, 37 younger adults and 38 older adults completed a similar task, now featuring three different photograph sequences (humorous, incongruous and neutral). Older adults exhibited no further effect of humor on memory when incongruity was controlled, whereas younger adults continued to recall humorous photographs better than neutral ones, in the two retrieval conditions. As expected, older adults also showed a negative effect of incongruity on memory, consistent with the inefficiency of their binding processes. Taken together, these studies show that the positive effect of humor on memory disappears in aging, owing to the inherent incongruity of humorous stimuli, combined with an associative memory deficit. (PsycInfo Database Record (c) 2025 APA, all rights reserved).