Two mirid bugs, Stenotus rubrovittatus (Matsumura) and Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae), are sympatric pests that infest rice in many regions of Japan. Three components, hexyl butyrate, (E)-4-oxohex-2-enal and (E)-hex-2-en-1-yl butyrate, in S. rubrovittatus and three other components, hexyl hexanoate, (E)-hex-2-en-1-yl hexanoate and octyl butyrate, in T. caelestialium, were identified as sex attractant pheromone components in these species. The synthetic pheromone lures for S. rubrovittatus do not attract T. caelestialium and vice versa. The attractiveness of the combination of two separate lures for the two mirid bugs within one trap (combination lures) and the attractiveness of a mixed lure, in which all six synthetic-pheromone components of both species were loaded onto a single septum, were compared with that of separate lures for each species in field experiments. Both the combination lures and the mixed lure were as attractive to males of both mirid bugs as the separate lures for each species in fields with gramineous plants. In paddy fields, the mixed lure was also as attractive to males of both species of mirid bugs as the separate lures for each species. These results suggest that the mixed lure and the combination lures could be useful as simultaneous monitoring tools for two sympatric major rice pests using a single trap.