The microwave spectrum of (cyclopropylmethyl)acetylene (a newly prepared compound) was investigated in the frequency range 28-40 GHz. Both gauche and cis conformers were observed, the latter being 64 +/- 30 cm(-1) lower in energy. The geometries of these conformers were obtained combining the ab initio and cm microwave spectroscopy results. A large-amplitude motion (the methylacetylene group torsion) was studied by assigning the rotational spectra of several torsionally excited states.