Let K be a subgroup of the inhomogeneous Hecke group G(5) of geometric level r. Then K is congruence if and only if K contains the principal congruence subgroup G(2r). In the case r not equivalent to 0 (mod 4), K is congruence if and only if K contains the principal congruence subgroup G(r). (C) 2014 Elsevier Inc. All rights reserved.