Forty-six patients with villous or tubulovillous tumors of the colon were examined to study the correlation between histologic and macroscopic or radiographic features and to define more accurately villous tumors of the colon. There was good correlation between the histologic and macroscopic or radiographic features. As villous elements became more prominent on histologic studies, the macroscopic appearance was more villous and granular but less nodular on the surface. Reticular and/or granular patterns with a feathery margin were more frequently seen on radiographs in cases of dominant villous elements. The macroscopic and radiographic characteristics of villous tumor frequently appeared when villous elements composed over 75% of the whole tumor on histologic studies. The authors propose that villous tumor of the colon can be accurately diagnosed when villous elements compose over 75% of the tumor.