A tentative detection of methyl isocyanide (CH₃NC) was reported by Cernicharo et al. in 1988. Three broadened rotational submilimeter transitions were found toward Sgr B2(OH) with the IRAM 30m telescope. The next evidence for the presence of CH₃NC in space was the reported detection of the J=1-0 transition at a centimeter wavelength observed with the Green Bank Telescope by Remijan et al. in 2005. In 2013, Gratier et al. confirmed the existence of interstellar methyl isocyanide with a detection toward the Horsehead photodissociation region, again using the IRAM 30m telescope. The 5 associated lines of the K-ladder of the J=5-4 transition were observed.

Methyl isocyanide is the less stable isomer of another detected astromolecule, methyl cyanide. Other detected X–N≡C compounds include hydrogen isocyanide (HNC), isocyanoacetylene (HCCNC), magnesium isocyanide (MgNC), aluminium isocyanide (AlNC), silicon isocyanide (SiNC), and hydromagnesium isocyanide (HMgNC).