A hyperbranched aliphatic polyether with hydroxyl end groups was produced from glycerol carbonate (4-hydroxymethyl-1,3-dioxolan-2-one)-the benign monomer obtained from renewable starting materials: glycerol and dimethyl carbonate. Anionic polymerization of glycerol carbonate, which proceeds with simultaneous decarboxylation, was performed using partially deprotonated trimethylolpropane (TMP) as an initiator. Pendant hydroxyl groups facilitate the ring-opening multibranching polymerization leading to a hyperbranched polyether. 13 C NMR analysis of the polymerization products confirmed the presence of linear, dendritic, and terminal repeating units. MALDI-TOF mass spectrum analysis confirmed the presence of TMP and glycerol core containing branched structures as well as a relatively small amount of macromolecules with cyclic groups. The polymers were soluble in water, THF, methanol and DMSO.