Evidence of female preference for dominant males during mating is reported for the rock shrimp Rhynchocinetes typus. Two sexually mature males of different ontogenetic stage were tethered at opposite sides of a large tank. Tethering restricted males from actively pursuing the receptive female but allowed females to choose between males. Surprisingly most (10 out of 11) females first approached the subordinate typus male, but after these initial contacts all females chose the dominant robustus male. Following antennal and corporal contacts of variable duration seven (out of 11) females initiated the mating process with the robustus male, while four females did not initiate mating during the 90 min observation period. The fact that all mating females selected the robustus shows strong female preferences for these males. It is suggested that female preference for large and dominant males is common among crustaceans with sexual size-dimorphism.