The microwave spectrum of the new molecular species CH 2FOH has been observed and analyzed. The molecule exhibits a gauche conformation which is in accord with previous ab initio calculations. This is also the conformation that is predicted based on anomeric effect arguments. The rotational transitions are split by the tunneling of the molecule between equivalent gauche conformations. A simultaneous fit of both tunneling states allows the determination of perturbation free rotational parameters as well as the tunneling frequency and a tunneling distortion parameter. A dipole moment analysis yields values of all three dipole moment components and the μbμc term which indicates that μb and μc have opposite signs.