In the title hydrated mol-ecular salt, C(11)H(14)N(3)O(+)·Br(-)·H(2)O, the Br(-) anion is split and appears as two independent half-occupied Br(-) anions on twofold rotation axes. The dihedral angle between the phenyl ring and the mean plane of the 2,3-dihydro-1H-pyrazole ring (r.m.s. devation = 0.014 Å) is 62.43 (7)°. In the crystal, the components are connected via O-H⋯Br and N-H⋯O hydrogen bonds to form a one-dimensional polymeric structure propagating along [001].