The aim of this study is to assess the prevalence of TTV infection in patients with malignancies and hematological disorders, who receive repeated blood transfusions. It is also intended to find out if there is any correlation between TTV and HCV, HBsAg, as well as liver affection (as evidenced by liver enzymes: AST & ALT). This study included 80 subjects divided into 5 groups: group I included normal healthy subjects, group II included 20 thalassemic patients, group III included 20 hemophilic patients, group IV included 10 patients with aplastic anemia, and group V included 10 patients with acute leukemia. All groups were subjected to history taking (especially history of blood transfusion), clinical examination, and laboratory investigations. The latter included CBC, liver function tests (AST & ALT), detection of HBsAg, detection of HCV antibodies, and detection of TTV). Detection of HBsAg and HCV antibodies was done by ELISA technique. TTV-DNA was detected by seminested PCR using two sets of primers. Then the PCR amplification products were detected by using gel electrophoresis and ultra-violet transillumination. The specific amplified bands were of 271 bp and they were compared with the DNA ladder marker. This study showed a significant positive correlation between the prevalence of TTV infection and the duration of blood transfusion (suggesting the quantity) in thalassemic patients. Also, there was a significant positive correlation between TTV infection and ALT & AST levels supporting its role in liver affection. Moreover, there was high frequency of TTV infection in HCV positive patients.