In the title compound, C(10)H(7)BrN(2), the non-H atoms, except the N atom of the acetonitrile group and the C atom bonded to it, lie in the least-squares plane defined by the atoms of the indole ring system (r.m.s deviation = 0.019 Å), with the N and C atom of the cyano group displaced by 2.278 (1) and 1.289 (1) Å, respectively, out of that plane. In the crystal, N-H⋯N hydrogen bonds link the mol-ecules into a C(7) chain along [100].