CaLaSiN3 samples doped with Eu, Yb, Sm, Ce and Pr have been prepared via solid-state reaction synthesis and the optical properties have been studied. Both Yb and Sm were only observed in the trivalent state due to the fact that their Ln(2+) ground states are located inside or very close to the conduction band of the CaLaSiN3 host lattice. Doping with Ce(3+) or Eu(2+) resulted in a very low energy Ce(3+) or Eu(2+) 4f-5d absorption band around 1.9 eV (650 nm) and 1.4 eV (885 nm), respectively. The Ce(3+) 5d-4f emission appeared to be quenched, just as the Eu(2+) 5d-4f emission, which can be explained as the result of auto-ionization.