Fish gelatin was exposed to ultraviolet treatment from 3 to 24 h. Ultraviolet-treated fish gelatin, after 6 h exposure exhibited the highest increase in gel strength. It was shown that doses above 9 h on tilapia gelatin can gradually decrease the gel strength. Partial insolubility of fish gelatin after more than 3 h of ultraviolet treatment was observed. Ultraviolet treatment did not change the Fourier transform infrared spectra of all ultraviolet-treated fish gelatin and control fish gelatin sample. The distribution of the molecular weights of gelatin treated with 3 to 24 h ultraviolet irradiation remained unchanged.