Humor is the ability to discern incongruity or lack of suitability. It performs many useful functions in the human life and in the society. As far as the use of humor in preaching is concerned there are arguments pro and contra. The article discusses both of them delivered from the Bible, the approach of the Fathers of the Church, theologians and the popes. One can find elements of humor in the Bible. There are convincing arguments that Jesus had a great sense of humor. In the history of preaching one may see the ambivalent approach to the use of humor in the pulpit. Currently however, both theologians and specialists in rhetoric and social communication recommend speaking with a smile and humor, as long as circumstances allow.