We report on the crystal growth, spectroscopic investigations, and the demonstration of visible laser operation of Pr,Mg:CaAl12O19. Crystals with dopant concentrations of 1 and 6xA0;at. % were grown by the Czochralski method. Polarization-dependent ground-state absorption and emission spectra as well as the excited state absorption characteristics were recorded in the visible spectral region. Furthermore, the decay dynamics of the P03 manifold and the radiative lifetime were determined. By employing a 6xA0;at. % doped Pr,Mg:CaAl12O19 crystal as gain medium and a frequency doubled optically pumped semiconductor laser as pump source, cw laser operation was realized at 644.3 and at 725.2xA0;nm. Maximum output powers and slope efficiencies exceeded 320xA0;mW and 25 respectively.