Mesoporous Ce0.4Zr0.6O2 solid solutions with four different shapes, including mixed nanorod and nanoparticle (RP, cubic), nanopolyhedron (PH, tetragonal), nanosphere (SP, cubic) and nanoegg (EG, tetragonal), were hydrothermally fabricated. Various physical and chemical techniqueswere used to reveal shape-dependent structural, optical, electronic andsurface properties, providing a powerful insight into the morphological dependence of photocatalytic activity towards methylene blue (MB) degradation. Among these samples, RP, consisting of a cubic Ce-rich phase (Ce0.6Zr0.4O2 nanorods) and a tetragonal Zr-rich phase (Ce0.2Zr0.8O2 nanoparticles), affords the optimal functionality, with a top degradation rate (D = 70.5%) and a peak rate constant (k = 0.0102 min(-1)). This occurrence results mainly from the prompt separation of excitons and suitable textural properties for MB absorption and activation. A brief introduction to the reaction path when using RP is proposed.