A review of literature indicates that humor could be related to pain tolerance through three possible mechanisms: cognitive emotional processes, changes in the neuroendocrine and immunological systems, and muscle relaxation. Seventy-two university students were exposed to a cold water pressor. While one of their hands was kept in cold water; one-third of them watched a humorous film, one-third watched a documentary film, and the last third was a control group. Subjects in each group were divided into high and low humor according to self-report questionnaires. The humorous film did not help control pain more than the documentary film. The only significant difference found between the groups was that subjects who watched the humorous film estimated the effectiveness of the film as higher. Furthermore, a positive relationship was found between tolerance of pain and sense of humor, especially with the capacity to produce humor. The results indicate that those who perceived the film as funny tolerated more pain, suggesting that humor helps only when perceived as such. The results are discussed in relation to other empirical evidence, and implications for further research are suggested.