In non-coordinating solvents, salt elimination between sodium tetracarbonylcobaltate and bulky alkylgallium chlorides yields almost quantitatively the novel volatile cobalt-gallium complexes of formula (CO)4CoGaR2(L) [3a: R = CH2C(CH3)3; 3b: R = CH2Si(CH3)3; L - THF]. The synthesized compounds were identified by means of H-1-, C-13-, P-31-NMR, MS, and infrared nu(CO) data. Additional, 3a was characterized by an X-ray single-crystal analysis. The sigma(Co-Ga) bond length is 257.8(3) pm. Those bonds are highly reactive and rapidly cleaved due to electrophilic or nucleophilic attack. 3a,b are used as canditates to generate intermetallic Co/Ga films by the procedure of low-pressure MOCVD.