The Przekop Wisły (or the Vistula Cross-cut) is a canal created 120 years ago in the Vistula River mouth to prevent floods. In 2013/2014, 82 samples of canal sediments were collected in the course of three sessions, which were next subjected to macroscopic descriptions and sieve analyses including calculation of granulation indices expressed in the phi scale. Characteristics of granulation are presented in relation to forms of bottom relief as well as varied transport and storage conditions of individual sessions. Sediments in the canal are relatively even-sized, with coarse and/or medium-grained sands, quite well-sorted, with moderately negative skewness and a leptokurtic distribution. It was demonstrated that deposition of sediments in the canal is progressing, especially in its estuarial section, which impacts significantly on its patency. Hence, it is necessary to monitor sediments in the canal in order to establish its condition and identify trends related to risks and flood prevention. The Przekop Wisły canal constitutes a natural area of a straight channel river, and studies of its sediments may be considered an important model of fluvial processes.