The author has collected those cases of cancer coli which during the period 1914—1926 were Röntgenologically examined and operated upon at the “Serafimerlasarettet,” besides such cases where the Röntgenological examination was indicative of tumorous infiltration in the intestines, but where no cancer was found to be present. The total number of cases is 63. A comparison has then been made between the reliability of the clinical findings, on the one hand, and the Röntgenologically findings on the other. With the one as well as the other method, one has reckoned, besides a diagnosis of cancer, tumour or infiltration, also intestinal obstruction or organic stenosis as “positive findings.” In the light of this consideration the Röntgenological examination has been positive in 86 per cent. of the cases and the clinical method in 56 per cent. Of the operable cases the Röntgenological examination has been positive in 91 per cent. and the clinical diagnosis in 48 per cent. Of the inoperable cases the Röntgenological examination gave positive findings in 82 per cent. of the cases and the clinical method in 70 per cent. In the advanced inoperable cases, where Röntgenological examination yielded uncertain results, one was able clinically to make a positive diagnosis. The methods have, therefore, complemented one another in an excellent manner.