In Lithuania, there were 476 new pancreatic cancer cases in 2005. Based on international scientific literature and the results of our retrospective studies, a prospective study has been designed. The aim of study was a prospective evaluation of the impact of two concomitant chemoradiation methods on the survival and the time to disease progression in patients diagnosed with resectable and unresectable pancreatic cancer and prospective evaluation of the safety of two concomitant chemoradiation methods for the treatment of resectable and unresectable pancreatic cancer. MATERIAL AND METHODS. During the period of 2000-2005 at the Clinic of Oncology, Kaunas University of Medicine Hospital, we performed a prospective randomized study to analyze two concomitant chemoradiation treatment methods. The patients were stratified according to the resectability of the tumor: with resectable tumor (stage I-IVA) and with unresectable tumor (stage III-IVA). Treatment for each group of patients was selected randomly choosing concomitant chemoradiation treatment: radiation therapy and 5-fluorouracil or radiation therapy and gemcitabine. Criteria of the efficacy of the treatment methods were median survival, time to disease progression, and treatment safety (qualitative and quantitative analysis). RESULTS AND CONCLUSIONS. The treatment methods - radiotherapy and 5-fluorouracil or radiotherapy and gemcitabine - were equally effective when assessing the survival and time to disease progression in patients diagnosed with pancreatic cancer. Treatment of patients diagnosed with pancreatic cancer with radiotherapy and 5-fluorouracil was a safer approach than treatment with radiotherapy and gemcitabine, which induced more severe toxic adverse effects.