A liquid chromatography with UV detection method has been developed and validated for the quantitation of di(2-ethylhexyl)terephthalate, a blood bag plasticizer, and its monoester metabolite, mono(2-ethylhexyl)terephthalate, in the four labile blood products: whole blood, red cells concentrate, plasma and platelet concentrate. Quantitation thresholds were compared with those obtained using the more conventional tandem mass spectrometry detection and revealed that UV performed better than mass spectrometry for the quantitation of di(2-ethylhexyl)terephthalate. Liquid-liquid extraction was selected for sample preparation. Recoveries ranged from 101 to 106 and from 80 to 83%, for di(2-ethylhexyl)terephthalate and mono(2-ethylhexyl)terephthalate, respectively, depending on the labile blood product. Repeatability and intermediate precision expressed as relative standard deviation were lower than 20% at the lower limit of quantitation and ranged from 1.9 to 11.2% for the other concentration levels. Regarding the trueness, bias ranged from -13.6 to 11.8%. The method was validated considering a total error of ± 20%. Lower limits of quantitation ranged from 500 to 680 nM for di(2-ethylhexyl)terephthalate and were equal to 500 nM for mono(2-ethylhexyl)terephthalate. Migration of di(2-ethylhexyl)terephthalate from polyvinyl chloride blood bags was investigated and mono(2-ethylhexyl)terephthalate concentrations were determined in each labile blood product.