The courtship behavior of an otitid fly, Physiphora demandata, is analyzed with a description of the 7 displays used by ♂♂ and the response of ♀♀ to courting ♂♂. ♂♂ employ the displays one after another to create highly variable courtship sequences that may consist of thousands of individual acts. The adaptive significance of such complex courtship is discussed. P. demandata may be an example of a species in which ♂♂ can neither control resources of significance to ♀♀ nor monopolize ♀♀ directly. As a result, female choice may be based purely on the demonstration of male genetic quality as shown by the ♂'s ability to hold a perch territory in an aggregation of ♂♂ and the ♂'s capacity to complete a demanding courtship routine.