Background: Colorectal cancer in HNPCC appears to have a better prognosis than sporadic colorectal cancer. Selection bias, screening, early intervention and treatment hamper efforts to confirm such a hypothesis.Aim: To evaluate survival rates in Lithuanian HNPCC patients with colorectal cancer and compare them with survival rates of sporadic cases arising from the general population. Patients And Methods: The study group consisted of 8 patients from 6 Hereditary non-polyposis colorectal carcinoma (HNPCC) families, 3 patients had HMSH2 and 5 patients had HMLH1 mutations, who were diagnosed between 1995 and 1999. HNPCC patients characteristic (age and stage) were used to trace the records of the Cancer Registry at the same period to identify the cases corresponding the required criteria. Above 263 patients were found--106 at stage II and 157 at stage III.Results: The 10-year survival was 87.5% in the HNPCC study group compared with only 44.8% in the general population group. Patients with the MSH2 gene mutation were at a greater risk of developing a second primary cancer independent from any cancer prevention and screening programs. Survival rates were also prolonged even with a greater numbers of extra-colonic cancers diagnosed at different stages.Conclusion: HNPCC patients with confirmed MSH2 or MLH1 mutations diagnosed with stages II and III CRC have a good 10-year survival prognoses compared with those from the general population.