Rotationally resolved, vibrational predissociation spectra of the HN+2–He complex have been recorded in the region of the N–H stretch (3100–3200 cm−1). The complex appears to be linear. Fitting of the measured lines to the pseudodiatomic expression ν=ν0+(B′ν+B″ν)m +(B′ν−B″ν–D′ν+D′ν) m2−2(D′ν+D″ν)m3 −(D′ν−D″ν)m4 yields the following constants: ν0=3158.419±0.009 cm−1, B″=0.3517±0.0005 cm−1, D″=(5.8±0.5)×106 cm−1, B′=0.3579 ±0.0005 cm−1, D′=(3.9±0.6)×106 cm−1. The data support a proton bound He–HNN+ structure, with a 1.72 Å vibrationally averaged intermolecular bondlength, and an approximate intermolecular stretching frequency of 150 cm−1.