In present work we have studied the irradiation induced effects in zinc ferrite nanoparticles with the help of Raman and Fourier-transform infrared (FTIR) spectroscopy. Zinc ferrite nanoparticles of different crystallite size ranging from 13 to 61 nm were irradiated with 200 MeV Ag15+ at three different fluences viz. 1 × 1012, 2 × 1012 and 4 × 1012 ions/cm2. Raman spectra of pristine samples exhibit the bands corresponding to Fd3m space group. These bands also appears in the spectra of irradiated samples, however their position is slightly shifted. Similar behaviour was also observed for the bands appearing in Fourier-transform infrared spectra. These bands broaden after irradiation. These changes have been attributed to the damage/crystalline disorder produced by swift heavy ion and the appropriate mechanism has been discussed in this regard.