Laser action has been observed on vibrational‐rotational transitions between low lying vibrational levels of HX and DX (X = F, Cl, Br) formed by chemical reactions in an electrically pulsed discharge. HF wavelengths, lying between 2.7 and 3.3 &mgr;, and DF wavelengths, lying between 3.6 and 4.2 &mgr;, are listed and identified.