Excitation functions of the reactions 89Y(p,n) 89Zr, 89Y(p,2n) 88Zr and 89Y(p,pn) 88Y were measured from their respective thresholds up to 17.7 MeV, with particular emphasis on data for the production of the medically important radionuclide 89Zr. The conventional stacked-foil technique was used, and the samples for irradiation were prepared by the sedimentation process. The excitation functions obtained were compared with those calculated theoretically using the ALICE-IPPE code. The measured data were also compared with the available literature values. From the experimental data the theoretical yields of the investigated radionuclides were calculated as a function of proton energy. The excitation function for the 89Y(p,n) 89Zr reaction measured in the proton energy range 5.1 to 17.7 MeV shows a pronounced broad peak in the energy range 16→11 MeV. On the other hand and because of the high threshold energy of the two other reactions 89Y(p,2n) 88Zr and 89Y(p,pn) 88Y, their excitation functions were measured only in the proton energy range 14.3 to 17.7 MeV. Differential and integral yields for the production of the three radionuclides were calculated. It was found that the suitable energy range for the production of 89Zr is 14→9 MeV; over this energy range the 89Zr amounts to 58 MBq/μA h. In the proton energy range provided by MGC-20 cyclotron [Ep(max)=18 MeV], only 89Zr can be produced in a suitable activity and with a high purity. Production of 88Zr and 88Y needs proton energy higher than that provided by this type of cyclotron.