The main mu-atomic transition energies in 89Y were measured with a high-resolution Ge(Li) spectrometer. The nuclear charge parameters of yttrium were derived by fitting the observed transition energies to those obtained by numerically solving the Dirac equation, using a radially symmetric Fermi charge distribution. The line intensities were also measured and shown to agree reasonably well with the results of a cascade calculation. Finally, we measured the energies and intensities of the most prominent capture γ rays. Most of these γ rays could be assigned to known transitions in the strontium isotopes 86 through 89.