The Judd–Ofelt analysis is applied to light-scattering ceramic CaSc2O4 doped with Tm3+. The calibration of the Judd–Ofelt parameters is performed by two approaches: (i) using the known magnetic-dipole contribution to the transition intensity of 3H6→3H5; (ii) using the radiative lifetime of an energy level supposed to decay mainly radiatively (1G4 or 3F4). The following results were obtained: Ω2=1.55×10−20cm2; Ω4=1.71×10−20cm2; Ω6=0.98×10−20cm2, using the first approach; Ω2=1.70×10−20cm2, Ω4=1.84×10−20cm2, Ω6=1.13×10−20cm2 (calibration using 1G4); Ω2=1.57×10−20cm2, Ω4=1.70×10−20cm2, Ω6=1.04×10−20cm2 (calibration using 3F4). The obtained Judd–Ofelt parameters are used to calculate the radiative lifetimes and quantum efficiencies of several Tm3+ levels, spontaneous emission probabilities and branching ratios of various Tm3+ transitions. A fairly good agreement was obtained between the results of these methods.