The rotational spectrum of difluoromethylene (CF2) in its (X) over tilde(1)A(1) ground electronic state has been observed using molecular beam-Fourier transform microwave spectroscopy. CF2 was produced in a free jet expansion in Ar as inert carrier gas by ArF excimer laser photolysis of CF2Cl2, CF2CHCl, or CF2CHBr or by flash pyrolysis of CF2Br2 in the high-pressure region directly behind a pulsed molecular beam valve. Rotational transitions were observed in the frequency range from 8 to 40 GHz in the CF2 (000) ground vibrational state and in the (100), (010), and (001) excited vibrational states. Several observed lines were split due to the hyperfine interaction between the F-19 nuclear spin and the overall rotation of the molecule. The results were used to determine the nuclear spin-rotation interaction parameters for CF2.