The high-spin-level structure of the nucleus 151Pm has been investigated by in-beam γ-ray spectroscopy using the 150Nd(α, p2N) 151Pm reaction. The observed enhanced E1 transitions with B(E1) of the order of 10-3 W.u. and parity doubling, both features characteristic of a reflection-asymmetric mean field, suggest an octupole deformation in 61151P