Pure rotational spectra of transition metal hydroxides have been reported. Millimeter wave spectra of CuOH and AgOH were recorded in a direct current discharge absorption cell in the range of 200-390 GHz. The spectra of both molecules correspond to that of a near prolate asymmetric top and only a-type R branch transitions were observed. The rotational and centrifugal distortion constants of CuOH and AgOH were precisely determined. Centrifugal distortion terms up to (NNz10)-N-2 were required to fit the observed line frequencies of (CuOH)-Cu-63. A preliminary analysis showed that AgOH is also strongly bent like CuOH with a bond angle smaller by about 2 degrees.