Two separate studies of the CD radical in vibrationally excited levels of its X 2 P ground state have been made by the technique of laser magnetic resonance. The first of these studies was in the far-infrared; rotational transitions of CD in the v ΒΌ 1 and 2 levels have been detected. The second study was carried out in the mid-infrared using a carbon monoxide laser magnetic resonance spectrometer. In these experiments, transitions in the (1,0), (2,1), and (3,2) bands have been detected. All the available data on CD in its X 2 P state have been used to determine an improved set of molecular parameters for the CD radical. In addition to the above data sets, previous far-infrared laser magnetic resonance on the CD radical in the v ΒΌ 0 level and FTIR observations of the (1,0) and (2,1) bands have been included. The principal molecular parameters determined are: m 0 ΒΌ 2032:03360 Γ°18Γ cm Γ1 , x e x e ΒΌ 34:72785 Γ°58Γ cm Γ1 , B 0 ΒΌ 7:7018632 Γ°14Γ cm Γ1 , a B ΒΌ Γa e ΒΌ Γ0:212239 Γ°11Γ cm Γ1 , where the figures given in parentheses are one standard deviation from the least squares fit. A small but significant dependence of the orbital contribution to the magnetic dipole moment on the vibrational quantum number is detected. This may reflect the mixing between the X 2 P and a 4 R Γ states of CD.