Résumé : Neutrons arising from the breakup of a 30 MeV/nucleon 19C beam on a tantalum target have been measured using the 98 element array DEMON. A narrow, forward peaked neutron angular distribution, with a corresponding momentum spread considerably smaller than those measured simultaneously for 21N, 22O and 24F, was observed for charged fragments with Z < Zproj. Interpreted in terms of the core-breakup reaction model, the results support the existence of a one neutron halo in 19C.