Background and objectives: Di(2-ethylhexyl) phthalate (DEHP) is a toxic plasticizer that is commonly used in the manufacture of polyvinyl chloride (PVC) blood bags. It is well known that DEHP can migrate from a medical device into the blood plasma. For safety reasons, pathogens in plasma must be inactivated; however, this process may increase DEHP migration. Here, we assessed the impact of illumination-based pathogen inactivation on the migration of DEHP from PVC bags into plasma. Materials and methods: Pairs of native PVC-DEHP plasma bags were pooled. Each pool was then split into a pathogen-inactivated bag and a control bag. After illumination, the plasma concentrations of DEHP and its main metabolite (mono(2-ethylhexyl) phthalate, MEHP) in each bag were assayed and compared using liquid chromatography-tandem mass spectrometry. Concentrations were evaluated in repeated-measures, two-way analyses of variance. Results: The MEHP concentration was significantly associated with storage but not with illumination (p = 0.0001). The DEHP concentration stayed constant throughout the storage period. The DEHP equivalent concentration (corresponding to the overall plasticizer migration rate into plasma) was not significantly associated with illumination (p = 0.3) or storage (p = 0.09; mean ± standard deviation of the mean DEHP concentration for all conditions: 147.9 ± 11.3 μg/ml). Conclusion: Illumination-based inactivation of pathogens in plasma did not increase the DEHP equivalent concentration, relative to control (non-inactivated) plasma. Keywords: DEHP; di(2-ethylhexyl) phthalate; metabolite; pathogen inactivation process; plasma.