Fe-Zn and Co-Zn heteronuclear carbonyl cation complexes are produced via a laser vaporization supersonic cluster source in the gas phase. The dinuclear FeZn(CO)(5)(+) and CoZn(CO)(7)(+) cation complexes are observed to be the most intense heterodinuclear carbonyl cation species in the mass spectra. The infrared spectra are obtained via mass selection and infrared photodissociation spectroscopy in the carbonyl stretching frequency region. Their geometric and electronic structures are assigned with the support of density functional calculations. The FeZn(CO)(5)(+) complex is determined to have a (OC)(5)Fe-Zn structure with a Fe-Zn half bond. The CoZn(CO)(7)(+) ion is established to have a staggered (OC)(4)Co-Zn(CO)(3) structure involving a Co-Zn sigma single bond.