By using a simple solution chemistry approach with polyvinyprrolidone (PVP) as a capping agent, Mn2W(CN)8·xH2O microcrystals with unique morphologies including rice-like, rod, octahedron, square platelet, and hollow-core square platelet have been successfully synthesized. The influence of experimental parameters such as reaction temperature, feed ratio of Mn2+ to PVP, reaction time, and reactant concentration on the morphology and size of Mn2W(CN)8·xH2O microcrystals were systematically investigated. The reaction temperature proved to be a key factor for morphological evolution of the products. It was found that 20, 55, and 85 °C were key points of morphological transformation. A possible growth mechanism of the Mn2W(CN)8·xH2O microcrystals is proposed.