In the crystal of the title compound, C11H14O4, the aromatic ring is almost coplanar with the 2-position methoxy group with which it subtends a dihedral of 0.54 (2)degrees, while the 5-position methoxy group makes a corresponding dihedral angle of just 5.30 (2)degrees. The angle between the mean planes of the aromatic ring and the propionic acid group is 78.56 (2)degrees. The fully extended propionic side chain is in a trans configuration with a C-C-C-C torsion angle of -172.25 (7)degrees. In the crystal, hydrogen bonding is limited to dimer formation via R-2(2)(8) rings. The hydrogen-bonded dimers are stacked along the b axis. The average planes of the two benzene rings in a dimer are parallel to each other, but at an offset of 4.31 (2) angstrom. Within neighbouring dimers along the {[}101] direction, the average molecular benzene planes are almost perpendicular to each other, with a dihedral angle of 85.33 (2)degrees.