A novel 3D homochiral manganese phosphonate with right-handed helical chains, [enH2]0.5Mn2[(HL)(L)] (1) (H3L = 2-hydroxyphosphonoacetic acid; en = ethylenediamine) has been synthesized by hydrothermal techniques. X-Ray diffraction analysis indicates that compound 1 consists of A channels with right-handed single helical chains, B channels with right-handed double helical chains and C channels with achiral channels that are connected through manganese centers and L3− ligands to form a homochiral coordination polymer. Surface photovoltage spectroscopy (SPS) of compound 1 indicates that it possesses positive SPV response in the range of 300–600 nm and shows p-type semiconductor characteristic. Magnetic susceptibility studies of compounds 1 reveal that there exist weak antiferromagnetic interactions between the manganese centers.