HgBa2Ca2Cu3O8+&dgr;(Hg‐1223) superconducting thin films of about 0.3 &mgr;m in thickness have been successfully synthesized. The process involves depositing films (∼ 1 &mgr;m thickness) of Ba2Ca2Cu3Oxon a SrTiO3substrate by pulse laser ablation technique and implanting mercury ions into this deposited film, followed by annealing at oxygen atmosphere. The films so obtained show a relatively wide superconducting transition temperature up to 118 K, as determined magnetically, which is similar to that of underdoping bulk Hg‐1223. ©1996 American Institute of Physics.