The microwave spectrum of the furan-CO van der Waals complex has been measured between 6-19 GHz with a pulsed nozzle Fourier transform microwave spectrometer, Due to a large amplitude motion of the CO subunit between two equivalent minima, the observed rotational transitions were split into two components. Their center frequencies were compatible with an asymmetric rotor with CO located above the plane of furan. The rotational spectrum has been analyzed using an effective model Hamiltonian that accounts for an internal rotation between furan and CO hindered by a low barrier.