The present study was conducted to determine the effect of high molybdenum (Mo) concentration on fluoride (F) uptake and remineralization of subsurface lesions utilizing acid cyclic methods in vitro. Bovine enamel with artificial subsurface lesions were treated with test solutions containing 1,000 ppm F (NaF) with and without 1,000 ppm Mo at pH 7.0. F uptake was analyzed using a microdrilling technique and remineralization was evaluated by polarized light microscopy. The results indicate that addition of 1,000 ppm Mo in a 1,000 ppm F solution modestly increases F uptake and promotes remineralization of subsurface lesions compared with 1,000 ppm F alone. These findings suggest that a high level of Mo may enhance the remineralizing activity of F in subsurface bovine enamel lesions in vitro.