In this study, the syntheses of bulks of Y-zeolite were attempted by a hydrothermal hot-pressing (HHP) method with various conditions such as the amounts and concentrations of NaOH solution, reaction temperatures, and reaction times. Dense bulks of Y-zeolite were successfully obtained by this HHP method. Under an optimum synthetic condition of HHP, solidified bulks of Y-zeolite possessed translucency with high values of specific surface area. Transmission electron microscopy observation of these translucent bulks of Y-zeolite showed that their microstructures were densified like polycrystalline ceramics sintered by heat treatments and no amorphous phase was observed at the boundaries of Y-zeolite grains. As a result, in these unique bulks of Y-zeolite synthesized by the HHP method, the microporous network was thoroughly connected at the grain boundaries of Y-zeolite.