We report a new kind of peptide-polysaccharide aerogel which was formed by the coassembly of the fluorenylmethyloxycarbonyl-diphenylalanine (Fmoc-FF) peptide and the polysaccharide konjac glucomannan (KGM). The porosity and hydrophobicity of the hybrid aerogels could be facilely tailored by modifying the mass ratio of Fmoc-FF and KGM. The aerogels with tunable architecture showed good performance for the separation of a wide variety of oil-water mixtures. The results provide an opportunity for the design of peptide materials as a new class of biocompatible absorbents with potential applications in biomedicine and separation.