Two emission band systems of SeO consisting of 46 bands degraded to longer wavelengths have been observed for the first time in the spectral region 10 780–9490 Å. The vibrational analysis of one system which consists of several double-headed bands shows that it arises from the forbidden transition b1Σ+–X3Σ−. The double-headed bands have been analyzed as belonging to the 1Σ+–X3Σ−(F1) and 1Σ+–X3Σ−(F2,F3) subsystems. The separations between the corresponding band heads of these two subsystems are consistent with the expected value of ~ 2λ, λ(= 86.4 cm−1) being the spin splitting constant of the X3Σ− state derived previously from a detailed rotational analysis of the B3Σ−–X3Σ− (denoted earlier as the A3Σ−–X3Σ−) system. The vibrational assignments are confirmed by the observed isotope band heads of 82SeO,80SeO,78SeO, and 76SeO. The second band system, which consists of a single sequence of bands in the region 10 780–10 500 Å, is tentatively assigned to the probable forbidden transition (a1Δ)–(X3Σ−).