Background: Thalassemia is the name of a group of genetic blood disorders. To understand how thalassemia affects the human body, you must first understand a little about how blood is made. Hemoglobin is the oxygen-carrying component of the red blood cells. It consists of two different proteins, an alpha and a beta. If the body doesn’t produce enough of either of these two proteins, the red blood cells do not form properly and cannot carry sufficient oxygen. The result is anemia that begins in early childhood and lasts throughout life. Since thalassemia is not a single disorder but a group of related disorders that affect the human body in similar ways, it is important to understand the differences between the various types of thalassemia. Aim: The aim of the research was to determine the prevalence of thalassemia and its characteristics among patients of a thalassemia center at Ibn-Alatheer hospital, Mosul /Iraq. Methods: This study was conducted on 86 cases over a period of one month from November 10,2017 until December 10, 2017.A specially designed questionnaire form has been prepared; this questionnaire was filled by direct interviews with thalassemic patients taking clinical and familial history then comparing them with their clinical profiles. Results: During the study period of 1 month, about 86 cases were studied. All patients were thalassemia beta major .The first degree consanguinity were 47(55%) from 86 patients. While second degree 31 (36%) from 86 patients. The last percentage were non consanguinity 8(9%) from 86 patients. The age of the patients ranged between 1 – 29 years old. The mean age was found to be 10 years old. All cases displayed abnormal Hb variability. Thalassemic females were 48(56%) while males were 38(44%). Conclusion: In view of the high prevalence of hemoglobinopathy of thalassemia in this region, a routine premarital screening program is needed for the identification and prevention of high-risk marriages and thus, prevention of the psychosocial trauma of bearing a transfusion-dependent child for life.