A trispecific antigen-binding molecule, wherein said molecule is an antigen-binding polypeptide dimer comprising a first polypeptide and a second polypeptide, each polypeptide having at least four antibody variable domains linked one after another, wherein (a) the first polypeptide comprises a first and a second antibody variable heavy domain linked with each other by a linker of 12 or less amino acid residues and a single chain Fv antigen binding unit having a third antibody variable heavy domain linked with an antibody variable light domain, said third antibody variable heavy domain and antibody variable light domain are capable to associate to a first antigen binding site, wherein the first or second antibody variable heavy domain is linked with the single chain Fv antigen binding unit by a peptide linker; (b) the second polypeptide comprises a first and a second antibody variable light domain linked with each other by a linker of 12 or less amino acid residues and a single chain Fv antigen binding unit having a third antibody variable light domain linked with an antibody variable heavy domain, said third antibody variable light domain and antibody variable heavy domain are capable to associate to a second antigen binding site, wherein the second antibody variable light domain is linked with the single chain Fv antigen binding unit by a peptide linker; (c) the first antibody variable heavy domain of the first polypeptide associates with the second antibody variable light domain of the second polypeptide to a third antigen binding site; (d) the second antibody variable heavy domain of the first polypeptide associates with the first antibody variable light domain of the second polypeptide to a fourth antigen binding site; and (e) two of said four antigen binding sites are specific for the same antigen. (a) the first polypeptide comprises a first and a second antibody variable heavy domain linked with each other by a linker of 12 or less amino acid residues and a single chain Fv antigen binding unit having a third antibody variable heavy domain linked with an antibody variable light domain, said third antibody variable heavy domain and antibody variable light domain are capable to associate to a first antigen binding site, wherein the first or second antibody variable heavy domain is linked with the single chain Fv antigen binding unit by a peptide linker; (b) the second polypeptide comprises a first and a second antibody variable light domain linked with each other by a linker of 12 or less amino acid residues and a single chain Fv antigen binding unit having a third antibody variable light domain linked with an antibody variable heavy domain, said third antibody variable light domain and antibody variable heavy domain are capable to associate to a second antigen binding site, wherein the second antibody variable light domain is linked with the single chain Fv antigen binding unit by a peptide linker; (c) the first antibody variable heavy domain of the first polypeptide associates with the second antibody variable light domain of the second polypeptide to a third antigen binding site; (d) the second antibody variable heavy domain of the first polypeptide associates with the first antibody variable light domain of the second polypeptide to a fourth antigen binding site; and (e) two of said four antigen binding sites are specific for the same antigen.