A (super)hydrophobic isocyanate based organic aerogel/xerogel/cryogel having a water contact angle of at least 90° comprising: a cross-linked porous network structure made of polyurethane and/or polyisocyanurate and/or polyurea, and hydrophobic compounds having before the gelling step at least one isocyanate-reactive group and no isocyanate groups Characterized in that said hydrophobic compounds are covalently bonded within the porous network of the aerogel/xerogel/cryogel and wherein said bondings are created during the gelling step of the formation of the isocyanate based organic aerogel/xerogel/cryogel cross-linked porous network structure.