The size and structure of contingents of patients with cancer, who had been posthumorously diagnosed as having this disease in the Tomsk Region in 2007 to 2011, were analyzed. The study was conducted on the basis of the data from the regional cancer registry. The proportion of posthumously registered cancer patients was greater than the average Russian value and equal to 8.1%; it was higher among males and did not differ in the urban and rural areas. The maximum rates of postmortem diagnosis were observed in cancer of the liver (33.9%), pancreas (25.0%), gallbladder (22.1%), and brain (21.3%). The paper provides evidence for measures to increase a control over posthumous cancer registration in the Tomsk Region.