Ultraviolet light amplification by the phosphorous chemiluminescence flame is observed in the 200–400‐nm region. PO &ggr;‐system emission is identified in the light amplification spectrum. Gaps in the amplification spectrum are attributed to the forbidden transitions:4II→X2IIof PO at 30 590 cm−1and5&Ggr;1→1,3&Ggr;0of PO excimer at 28 117 cm−1. Light amplification by the phosphorus chemiluminscence system is interpreted as an incipient lasing action.