Polyamide foams which do not propagate fire are obtained by mixing (i) a liquid isocyanate component which comprises at least one polyisocyanate and in which the molar ratio of aromatic isocyanate groups to the sum of aromatic and aliphatic isocyanate groups is at least 60 mol %, with (ii) at least one liquid isocyanatereactive component which comprises a reactive diluent, and the reactive diluent 10 comprises (a) a chain-extending and/or crosslinking reactive diluent selected from among aliphatic branched C24-66-polycarboxylic acids, alicyclic C24-66-polycarboxylic acids and partial esters of polycarboxylic acids having at least two unesterified carboxyl groups and/or (b) a chain-terminating reactive diluent selected from among aliphatic branched C24-66-monocarboxylic acids, alicyclic C24-66-monocarboxylic acids and partial esters of polycarboxylic acids having one unesterified carboxyl group, wherein the liquid isocyanate-reactive component comprises an aromatic C8-18-polycarboxylic acid and/or an anhydride thereof.