The vacuum UV spectra of methylenecyclopropane, methylenecyclobutane, methylenecyclopentane, and methylenecyclohexane have been obtained from 45 000 to 70 000 cm(-1). The transitions for methylenecyclopropane have been calculated at the EOM-CCSD/6-311(2+,2+)G** level. Using the equilibrium C=C bond lengths, the calculated transition energies are uniformly larger than observed, but increasing the bond length a small amount led to quite good agreement. Here, the transitions are found to originate from the two higher energy occupied cyclopropane ring orbitals in addition to the pi orbital. The transitions for methylenecyclohexane are found to be linearly related to those for isobutene. CIS calculations for all of the methylenecycloalkanes using somewhat lengthened C=C bonds reproduced the lower energy transition energies fairly well.