Increased thrombophilic tendency in patients with cystic fibrosis (CF) has recently been reported. The determinants of thrombosis in children with CF remain largely unknown. Our aim in this study was to evaluate the thromboelastography (TEG) profile of children with CF through ROTEM (whole blood rotation thromboelastometry). Nineteen patients with CF and 20 controls were included in the study. Whole blood count, prothrombin time, activated prothrombin time, fibrinogen, d-dimer levels, and ROTEM assays (INTEM, EXTEM) were performed. Clotting time, clot formation time (CFT), and maximum clot firmness (MCF) were determined by INTEM and EXTEM analysis. In INTEM assay, MCF (P = .001) value was significantly increased and CFT (P = .031) value was decreased in patients with CF compared with those of the control group. In the EXTEM assay, there was a similar significant increase in MCF (P = .023) value in patients with CF compared with that of the control group. There was a significant positive correlation between fibrinogen levels and MCF in EXTEM (r = .72) and INTEM (r = .76) assays, whereas there was a negative correlation with CFT in EXTEM (r = -.61) and INTEM (r = -.67). The results of our study indicated that TEG profiles in patients with CF were more hypercoagulable compared with those of the control group.