Nintendo sold 479,931 units of the Wii in the four weeks to Jan. 27, compared with 165,719 units of the PS3, Enterbrain said on Friday.
The Wii was the top-selling console in Japan for the second straight month, it said.
"This year, attention will shift to how hardware sold will propel the game market," Enterbrain said in a release.
The numbers were compiled prior to the Jan. 31 launch of Nintendo's "Super Smash Bros. Brawl" combat game featuring the Mario Brothers and other characters, which the publisher called "promising".
Sales of "Wii Fit," which features a pressure-sensing board that players can use to simulate ski jumps or surfing, topped 1.21 million units in the nine weeks since its release.