A single male Dusky Warbler was observed at the Yodogawa River, in Osaka City, from January 4 to April 4, 1999. This is only the second record in Japan, and the first record in Honshu. The bird feeds on small insects among a thick growth of Reed Phragmites karka. The bird's call note is similar to Bush Warbler Cettia diphone, but its call was weaker and the volume lower. The bird was distinguished as a male P. fuscatus by its shape, coloring and call note.