Very long threadlike micelles observed in aqueous solutions of some surfactants have attracted much attention because of the peculiar theological properties of these systems, Molecular dynamics simulations have suggested that branched threadlike micelles should exist in concentrated solutions of dimeric surfactants. Here experimental evidence, obtained from transmission electron microscopy at cryogenic temperature, is presented of branched threadlike micelles in aqueous solutions of a triquaternary ammonium (trimeric) surfactant made up of three amphiphilic moieties connected at the level of the headgroups by two propanediyl spacers.