The à 2Δ-X̃ 2Π electronic transition of the CCN free radical was observed in emission with a high-resolution Fourier transform spectrometer. The CCN was jet-cooled in a corona-excited supersonic jet expansion of diazoacetonitrile (HC(N 2)CN) in helium. From the 000-000, 000-001, 000-002, and 000-100 vibronic bands spectroscopic constants were derived including the ground-state vibrational frequencies, v3 = 1050.7636(6), 2v3 = 2094.8157(18), and v1 = 1923.2547(69) cm-1. © 1990 American Institute of Physics.