Objective: Trituration of food in the oral cavity and stomach is required to achieve sufficient absorption of nutrients from food. Insufficient masticatory performance may increase the functional burden of the stomach and slow down gastric emptying (GE). Pera and coworkers (J Dent Res 81:179–181, 2002) showed that doubling the number of masticatory cycles hastened the GE of identical test meals and thus concluded that food trituration significantly affected GE. However, independent influences of the number of chewing cycles and the degree of food trituration have not yet been clarified. This study aimed to investigate the influences of mastication and food trituration on GE. Methods: GE of solid food was studied in 15 normal adult males by using the 13C-octanoic acid breath test. A test meal that contained ham cubes, breads, and an egg mixed with 13C-octanoic acid was divided into nine equal portions. Measurements were repeated three times for each subject by changing the chewing conditions as follows: fine or coarse chewing (each portion of the test meal was consumed in 60 and 20 chewing cycles, respectively) and coarse chewing preceded by 10min of gum chewing. Two GE parameters—maximum excretion time (Tmax) and gastric half-emptying time (T1/2)—were compared statistically among the three chewing conditions with the Freedman test. Results: No significant difference was observed in the GE parameters among the three conditions. Although the mean Tmax and T1/2 of coarse chewing were 13min and 21min longer than those of fine chewing (Tmax: 122±36min vs. 109±25min; T1/2: 207±62min vs. 186±50 min), those of coarse chewing preceded by gum chewing (Tmax: 111±22min; T1/2: 187±39min) were almost identical to the results of fine chewing. Conclusion: Food trituration had limited influences on GE; chewing itself might have increased gastric motility and hastened GE.