The structure-property relationships of polyurea aerogels made using two aromatic diamines and a triamine crosslinker are compared. Diamines were chosen based on previous work reported on polyimide aerogels. Polyurea segments were created by reacting one diamine species with 4,4’-diphenylmethane diisocyanate (MDI) in anhydrous N-methyl-2-pyrrolidone (NMP). These isocyanate-capped segments were crosslinked with 1,3,5 triaminophenoxylbenzene (TAB). Gels were dried under supercritical condition after exchanging the solvent with liquid carbon dioxide. The aerogel articles were obtained with density between 0.20 and 0.23 g/cm3, average pore sizes between 11-15 nm, porosity between 81-86%, and surface area between 111 and 394 m2/g, and onset of thermal decomposition at 250 °C.