Rare-earth ions in dielectric crystals play an important role in high-resolution laser spectroscopy and are interesting candidates for storing quantum states of photons. We characterize the praseodymium hyperfine interaction of the ground-state (3H4) and one excited-state (1D2) for two important compounds: praseodymium doped in yttrium aluminum perovskite and praseodymium doped in yttrium orthosilicate. The spin Hamiltonian parameters are determined by numerical analysis of Raman-heterodyne spectra, which were collected for a range of static external magnetic field strengths and orientations. For Pr3+:YAlO3, we present a full analysis without restrictions for the Zeeman and quadrupole tensors, and our new characterization for Pr3+:Y2SiO5 resolves a controversy in the literature.