Measurements have been made of the absorption and fluorescence spectrum of Cr3+in orthorhombic YCrO3, LuCrO3, and GdCrO3. We observe several very sharp emission lines at energies about 100 cm−1lower than the intrinsic4A2to2ECr3+absorption, and attribute the emission to impurity‐perturbed Cr3+ions. Intrinsic emission was not observed. Magnon sideband fluorescence is found at lower energy and results in the simultaneous optical de‐excitation of a perturbed Cr3+ion and the creation of a magnon on a neighboring lattice site. The sideband is spin allowed if the photon and magnon are created on the same sublattice, and has electric dipole polarization. Analysis of the sideband line shape shows the nearest‐neighbor exchange interaction between pairs along thecaxis, and between pairs in the plane perpendicular to thecaxis are not equal. The value ofJaveraged over the six nearest neighbors is 22.1, 17.6, and 25.5 cm−1for the Y, Lu, and Gd chromites, respectively. These results are in good agreement withJvalues computed from magnetic data.