Several ionic liquids were applied as catalysts for the synthesis of cyclic urethanes from amino alcohols and pressurized CO2 in the presence of alkali metal compounds as promoters. A comparative study was made for the catalytic performance using different ionic liquids, substrates, promoters, and pressures. The optimum catalytic system was BMIM-Br promoted by K2CO3, which, for 1-amino-2-propanol, produced cyclic urethane in 40% yield with a smaller yield of substituted cyclic urea and no oligomeric byproducts. For other amino alcohols, cyclic urethanes, cyclic ureas, and/or undesired byproducts were produced in different yields depending on the substrates used. Possible reaction mechanisms are proposed.