We report optical properties of nano- and micro-structures of YBO 3:Eu3+ synthesized using a hydro(solvo)thermal approach. Photoluminescence (PL) properties were examined under different excitation wavelengths, ranging from the deep to the near ultraviolet. Single crystal nanoflakes gathered together to evolve into a hierarchical structures through self assembly processes with eight different types of three dimensional morphologies. The samples show strong orange (O) and red (R) PL at 591, 611, 627 nm at all excitation wavelengths. The PL originates from 5D 0 - 7FJ (J = 1, 2, 3, 4) transition levels of Eu3+. YBO3:Eu3+ prepared using ethanol solvent has the highest R/O ratio with chromaticity coordinates. We observed that the R/O ratio increases as we go from deep to near ultraviolet excitation, making them attractive candidate for producing red emission in white light emitting diodes.