First, previously unknown, cyclic organogermanium peroxides, 1, 2, 4, 5, 7, 8-hexaoxa-3- germonanes, were synthesized by the reaction of 1, 1′-dihydroperoxydi (cyclododecyl) peroxide with (di) alkyl (aryl) dihalogengermanes. The new compounds have a higher tendency to undergo hydrolysis compared to silicon-containing analogs.