Photolysis of Cp*Fe(CO)2SiMe3 (3) in the presence of p-TolGeH3 (4) gave a mixture of cis and trans mono(germylene)-bridged diiron complexes, Cp*2Fe2(CO)2(μ-CO)(μ-Gep-TolH) (cis-5, trans-5), a mixture of two kinds of trans bis(germylene)-bridged diiron complexes, Cp*2Fe2(CO)2(μ-Gep-TolH)2 (syn-trans-6, anti-trans-6), and a complex with two Fe⋯H⋯Ge 3-center 2-electron bonds, Cp*2Fe2(CO)2(μ;-Gep-TolH 2)2 (7). A cis isomer of complex 6 (syn-cis(H)-6) was formed as the sole product by the thermolysis of complex 7. Photolysis of 7 or syn-cis(H)-6 resulted in the conversion to a mixture of syn-trans-6 and anti-trans-6. Reversible thermal and photochemical interconversion between cis and trans isomers of complex 5 was observed. The molar ratio of the cis and trans isomers of complex 5 in C6D6 was 7:93 at thermal equilibrium at 55°C and 84:16 at the photostationary state at 6°C.