BACKGROUND A value set for the EuroQoL 5-Dimensions (EQ-5D)-Y in Slovenia is not yet available, making the calculation of quality-adjusted life-years (QALYs) for children and adolescents using this generic instrument impossible. OBJECTIVE The main objective of our study was to obtain adult preferences towards EQ-5D-Y health states in Slovenia, following the EQ-5D-Y-3L international valuation protocol. The adults were asked to take the perspective of a hypothetical 10-year-old child. METHOD A sample of 1074 adults in Slovenia completed an online discrete-choice experiment (DCE) survey on EQ-5D-Y health states. The latent scale issue was addressed by obtaining the value of the anchor (33333) with 200 composite time trade-off (cTTO) interviews. A mixed (random coefficients) logit model was used to estimate the value set. Results All the estimated coefficients of the mixed logit model were statistically significant at the 1% level and had an expected negative sign. The most important health dimension in EQ-5D-Y is pain/discomfort, followed by anxiety/depression, usual activities, and mobility, with self-care being the least important health dimension. CONCLUSIONS The study addresses an important research gap and presents the EQ-5D-Y value set for Slovenia. At the time of writing, no published value sets are available for the EQ-5D-Y-3L appropriate for use in QALY calculations, making this value set the first EQ-5D-Y value set in the world.