Nafion ® -H, a perfluoroalkanesulfonic acid resin, has been found to be a suitable solid acidcatalyst with high selectivity and catalytic activity for the one-potsynthesis of fluorinated benzimidazolines, benzothiazolines, benzoxazolines, and dihydrobenz-oxazinones. These Nafion ® -H mediated condensation-cyclization reactions were easily achieved under mild conditions in high yields and purity.