Yellow crystals of the phosphorusselena bromide α-P4Se3Br2 [monoclinic, C2/c, Z = 8, a = 12.724(3) A, b = 14.732(3) A, c = 12.553(3) A, β = 116.60(3)°] were obtained from the reaction of P4Se3 and bromine at 80 °C in sealed glass ampoules. The crystal structure features discrete molecules of the formula α-P4Se3Br2 according to the well-known α-form of P4Ch3I2 molecules (Ch = S, Se).