We have investigated the spectroscopic properties of praseodymium ion in a Y3Al5O12 sample. We obtained the luminescence spectra by exciting selectively the sample at 460 and 599 nm, resulting in the excitation of the P-3(0) and D-1(2) levels, respectively. With excitation in the P-3(0) level we obtained emission from this level and from the D-1(2) level. We used time resolved spectra and decay pattern inspection to assign spectral lines to specific radiative transitions. With excitation in the D-1(2) level we observed luminescence emitted by the same level and upconverted emission from the P-3(0) level and the (4f5d) band. The experimental data indicate that the mechanism responsible for the upconversion processes is excited state absorption. We found the upconverted emission from P-3(0) and the (4f5d) band to be proportional to the square of the excitation energy and to the cube of the excitation energy, respectively. (C) 2005 American Institute of Physics.