Porous Al2O3 ceramics were fabricated using a rapid gelation to fix the foam structure after mechanical foaming. The slurry was made with deionized water, Al2O3 powder, a water-soluble copolymer of isobutylene and maleic anhydride, and a surfactant. The resultant gel formed at room temperature in air. The influence of the surfactant (EMAL TD) content on gelling behavior, pore structure (porosity, cell size), shrinkage behavior, and compressive strength of the resultant porous Al2O3 ceramics was evaluated. Porous Al2O3 ceramics were sintered in only one step without debinding because of the low concentration of additives (≤0.5 wt%). The porous Al2O3 ceramics had porosities from 20 to 89% and cell sizes from 60 to 220 μm. The compressive strength was 75 MPa when the porosity was 60%.