The rotational spectrum of the hydrogen bonded dimer formed between methylenecyclopropane and hydrogen chloride has been obtained with pulsed-supersonic nozzle Fourier-transforn microwave spectroscopy. Analysis of rotational constants and quadrupole coupling constants for three isotopic species of the dimer shows that HCl is attached to the C=C bond of methylenecyclopropane in a T-type configuration. The HCl monomer lies in or very near the plane that bisects the cyclopropyl ring, with the Cl atom lying 3.569 Angstrom from the center of the C=C bond. The HCl axis is bent towards the three membered ring and there are experimental indications of a near 20 degrees bend in the hydrogen bond. The observed dimer geometry is consistent with an electrostatic model which predicts the alternative configuration with HCl T bonded to the edge of the ring (as in cyclopropane-HCl) to be less stable when the base is methylenecyclopropane.