Stimulated emission on theB→Xband of CdI and isotopically enriched (98.6%)114CdI has been observed in a UV‐preionized, transverse discharge device with a gain length of 50 cm. For natural CdI, the laser energy is distributed among several transitions between 656 and 658 nm. The isotopically enriched114CdI spectrum, in contrast, is dominated by a single line at 657.1 nm, which contains >50% of the output energy. With a high‐Qoptical cavity, output energies >10 &mgr;J have been measured in a 85‐ns full width at half‐maximum (FWHM) pulse.