Abstract:A survey on the ecology of the brown-banded cockroach, Supella longipalpa (Fabricius) in Japan, revealed that the species has already established itself in metropolitan Tokyo, and 4 other prefectures, namely, Kanagawa, Fukuoka, Nagasaki and Okinawa. A total of 15 individuals, consisting of 4 male adult, 6 female adult and 5 nymphs, were collected from the hotel guest rooms, residential house and kitchen of a ship moored in the Sasebo harbour. In the collection of the cockroaches at the residential house, the adults, nymphs and oothecae were found in the kitchen, living room, bedroom and toilet. Since there had been no report of this species from the mainland Japan to date, this paper presents the first record of this species showing that it has already invaded the Japanese mainland.