Background: Non-valvular atrial fibrillation (AF) is the most common cardiac arrhythmia with a prevalence as high as 1.5±2.0% in the general population. This arrhythmia remains one of the major causes of stroke, heart failure, sudden death, and cardiovascular morbidity in the world. The aim of study was to evaluation of the patients in delta region who have non-valvular AF and on oral anticoagulation with Vitamin K antagonist as regard the time they spend within therapeutic range. Patients and Methods: A total of 100 patients were included in this study for evaluation of the patients in delta region who have non-valvular AF and on oral anticoagulation with Vitamin K antagonist as regard the time they spend within therapeutic range. Results: Our study showed that only 35% achieved the recommended TTR (percent time in therapeutic range) above 60% from studied risk factors, none showed statistical significance. Conclusions: The quality of anticoagulant control was lower that reported in European countries with a significant proportion of patients had TTR below 60%.