Abstract Saturation in YBa 2(Cu 1−xZn x) 3O 7- δ has been studied in relation to phase composition. Nominal compositio up to x=0.3 have been synthesized by an optimized 3 steps solid state route. Values as high as x=0.12 were observed at nominal zinc content where secondary phases appear (x≥0.1). Mixtures of pure YBa 2Cu 3O 7− δ with ZnO were also sintered. In this case, x is never higher than 0.07. Rietveld refinement applied to X-ray diffraction datas shows that the orthorhombic character of the YBa 2Cu 3O 7- δ lattice is maintained in the range 0≤x≤0.12. Correlations between zinc saturation and Y 2O 3BaCO 3CuO phase diagram are established.