We have studied phosphorus doping into CuInS2 using InP as a p‐type dopant. When the charged amount ratio InP/In was in the region of 3.5 × 10–4 ≤ InP/In (mole fraction) ≤ 1.3 × 10–2, p‐type bulk crystals were grown in the S‐poor alloy composition region. The activation energy of the phosphorus acceptor is estimated to be 117 meV from Hall measurement. The hole mobility is about 10 cm2/Vs at 300 K (p ∼ 1 × 1015 cm–3).This low mobility is probably due to the high compensation of S‐vacancy donors. The donor‐acceptor pair emission associated with phosphorus acceptors was observed in phosphorus doped CuInS2. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)