We report the magnetic structure of TaFe 1+yTe 3 single crystals by means of neutron diffraction measurements. TaFe 1+yTe 3 possesses a layered structure with a formation of two-leg zigzag ladders along the b axis. We find that TaFe 1+yTe 3 undergoes an antiferromagnetic transition at 178 K with Fe1 spins of the intraladders ferromagnetically aligned and with Fe1 spins of the interladders antiferromagnetically coupled. Furthermore, spins of the neighboring interstitial Fe2 (y) ions align parallel to the Fe1 spins of each ladder. These findings are distinct from the magnetic structure of the recently discovered spin-ladder compound BaFe 2Se 3. TaFe 1+yTe 3 may serve as a model system for investigating the interesting physics of quasi-one-dimensional ferromagnetic systems.