Two cases of multiple lymphomatous polyposis (MLP) are presented, involving different segments of the gastrointestinal tract. Both cases display the characteristic clinical and pathologic features of MLP. In addition, we were able to document, for the first time, the endoscopic ultrasonographic findings in this disease. This new ancillary diagnostic technique was found to be very helpful in the evaluation of the structural changes of the wall of the gastrointestinal tract and in the detection of affected lymph nodes.