It is required to have two diabetes positive oral glucose tolerance tests for the diagnosis of diabetes mellitus.This study is a multi-national , multicentre , open labelled , randomized and prospective controlled parallel group 's trial , with 24 months treatment.The primary objective of this trial is to compare the glycaemic control of oral therapy with Repaglinide with insulin injections in patients with cystic fibrosis related diabetes after 2 years of treatment.The trial should include 74 subjects showing cystic fibrosis related diabetes newly diagnosed by oral glucose tolerance test during annual screening for cystic fibrosis related diabetes.Patients are randomised by central fax randomisation.Primary endpoint is mean HbA1c after 24 months of treatment .