Isocyanoacetylene (HCCNC) was detected back in MCMXCII by Kawaguchi et al. toward the giant Taurus Molecule Cloud 1 (TMC-1) using the 45m telescope at Nobeyama Radio Observatory. Three observed rotational transitions were assigned to HCCNC by this study, but one of them was more ambiguous than the others. A survey of TMC-1 published in 1998 by Ohishi & Kaifu that assigned one additional line to HCCNC is the only further confirmation of the species to date.

Isocyanoacetylene is an isomer of cyanoacetylene, which has been a known astromolecule since 1971. Other isocyano species that have been discovered in astrophysical sources to date include hydrogen isocyanide (HNC), magnesium isocyanide (MgNC), hydromagnesium isocyanide (HMgNC), methy isocyanide (CH₃NC), aluminum isocyanide (AlNC), and silicon isocyanide (SiNC).