The benzene ring in the title compound, C(10)H(10)O(4), makes an angle of 4.4 (1)° with the C-C-C-O linker. The hy-droxy groups are involved in both intra- and inter-molecular O-H⋯O hydrogen bonds. The crystal packing is stabilized by O-H⋯O hydrogen-bonding inter-actions. The mol-ecules of the caffeic acid ester form a dimeric structure in a head-to-head manner along the a axis through O-H⋯O hydrogen bonds. The dimers inter-act with one another through O-H⋯O hydrogen bonds, forming supermolecular chains. These chains are further extended through C-H⋯O hydrogen bonds as well as van der Waals inter-actions into the final three-dimensional architecture.