Absorption spectra of REOCI (RE = La, Pr, Gd and Y) have been measured in the range 435–950 nm at ambient, liquid nitrogen and liquid helium temperatures. Luminescence from the ³P₁, ³P₀ and ¹D₂ levels in PrOCI, LaOCI/Pr³⁺, GdOCI/Pr³⁺ and YOCI/Pr³⁺(Pr³⁺ content 2 mol%) was observed under argon-ion laser excitation in the visible region between 475 and 800 nm. The transitions were assigned and the energy-level scheme derived from absorption and emission spectra and consisted of some 50 levels; i.e. 68 Stark components out of 91 for the 4f² configuration. This set was fitted to a Hamiltonian of 13 adjustable parameters including free-ion [Racah's (E_0–3), Tree's (α, β and γ) and spin—orbit coupling constant (ζ) as well as crystal-field (B²₀, B⁴₀, B⁴₄, B⁶₀ and B⁶₄) parameters. Good simulation of the experimental energy-level scheme was achieved with a root mean square deviation equal to 17 cm^–1. A comparison with the energy-level parametrization of Nd³⁺(4f³) in NdOCl, as well as of Eu³⁺(4f⁶) and Tb³⁺(4f⁸) in GdOCl, shows the consistency of the present results.