This study was conducted to determine the fluoride intakes in 94 preschool children aged 3, 4 and 5 (n = 30, 30, 34, respectively) residing in Yokkaichi, Mie Prefecture (< 0.16 ppm F water supply). The parents duplicated all the diets that their children ingested on 3 separate days during a 1-year period. The acid-diffusible fluoride in the diet was isolated by the acid-diffusion technique and measured with a fluoride electrode. The mean daily fluoride intakes from diet alone by children aged 3, 4 and 5 were 0.30 mg (n = 29, SD 0.19), 0.28 mg (n = 30, SD 0.19) and 0.30 mg (n = 34, SD 0.19), respectively. The total estimated mean values from diet and dentifrice were 0.35 mg (n = 29, SD 0.22, range 0.13–1.00), 0.33 mg (n = 30, SD 0.19, range 0.13–0.86) and 0.39 mg (n = 34, SD 0.18, range 0.18–1.01), respectively. It was concluded that the mean (±SD) total fluoride from diet and dentifrice in 3- to 5-year-old Japanese children was 0.35 ± 0.19 mg/day (0.021 ± 0.012 mg/kg body weight).