[Objectives]  To determine the effectiveness of dressing seeds with triflumezopyrim as a means of controlling the brown planthopper Nilaparvata lugens (Stål). [Methods]  The population dynamics of N. lugens adults and nymphs were surveyed in paddy fields after host plant seeds had been dressed with triflumezopyrim between 2019 and 2021. [Results]  Dressing seeds with ≥ 50.0 ga.i./hm² (grams active ingredient per ha) doses of triflumezopyrim delayed the first appearance of both adults and nymphs by ≥ 19 days and 25 days, respectively. Population density decreased substantially in all plots treated with triflumezopyrim, indeed, there was not a single day on which the population density in triflumezopyrim treated plots reached the control threshold. The level of control achieved by dressing seeds with triflumezopyrim exceeded 94% over 53 days. Even when the survey was extended to 102 days, control still exceeded 94% at dosages of ≥ 50.0 ga.i./hm². [Conclusion] Dressing seeds with ≥ 50.0 ga.i./hm² triflumezopyrim can effectively control the sixth and the seventh generations of N. lugens, thereby reducing pesticide use and simplifying cultivation.