The microwave spectrum of methyltrichlorogermane has been investigated in the region 26.5 to 40.0 GHz. The ground state rotational constants, B, were found to be 1602.19, 1601.42, 1601.10, 1600.71, 1600.02, 1537.84, 1537.10, and 1536.36 MHz for the symmetric top molecules CH 3 70Ge 35Cl 3, CH 3 72Ge 35Cl 3, CH 3 73Ge 35Cl 3, CH 3 74Ge 35Cl 3, CH 3 76Ge 35Cl 3, CH 3 70Ge 37Cl 3, CH 3 72Ge 37Cl 3, and CH 3 74Ge 37Cl 3, respectively. For the asymmetric top molecules CH 3 72Ge 35Cl 2 37Cl and CH 3 74Ge 35Cl 2 37Cl the ground state rotational constants A, B, and C were found to be 1597.96, 1559.31, 1203 and 1597.17, 1558.59, 1207 MHz, respectively. From the rotational constants the r s values for the GeCl bond distance of 2.135 ± 0.006 Å and the CGeCl bond angle of 106.0 ± 0.7° were obtained. The centrifugal distortion constant for the CH 3Ge 35Cl 3 species was calculated to be 0.35 ± 0.08 kHz. The Raman spectra of methyltrichlorogermane has been recorded in the gas phase and the methyl torsional overtone (Δ ν = 2) was observed. From the observed frequency shift the barrier to internal rotation has been calculated to be 1.45 kcal/mole.