TT virus (TTV) is a naked, single stranded DNA virus, which has been discovered in the serum of a patient with posttransfusion hepatitis of unknown etiology. TTV is widespread in the population, however, the mode of its transmission is unclear. This study was conducted to search for TTV-DNA positivity rates and its relationship with the clinical outcomes of recipients who underwent multiple blood or blood product transfusion, together with healthy children. TTV-DNA was investigated in 52 multitransfused pediatric patients (age range: 3 mnths - 17.5 yrs, mean age: 9.2 +/- 5.7 years) and 18 healthy children (age range: 1 mnth - 16.5 yrs, mean age: 8.1 +/- 4.9 years), by qualitative in-house semi-nested polymerase chain reaction (PCR) with the primers NG059, NG061 and NG063, generated from ORF1 region of the viral genome. TTV-DNA was found positive in 30.8% of multitransfused, and 16.7% of healthy children. The differences of TTV-DNA positivity rates between the multitransfused and control groups, and ALT values between the patients with positive and negative TTV-DNA, were statistically insignificant (p>0.05). As a result, no relationship was detected between TTV positivity and hepatitis, although there was a statistically insignificant increase of TTV-DNA positivity in multitransfused children. However, since the primers of ORF1 N22 region used in our PCR method did not have enough sensitivity for the detection of TTV-DNA, it has been concluded that more sensitive primers such as UTR primers, should be used for more reliable evaluation of the results.