Summary  The aim of this study was to evaluate the association between masticatory performance (MP) and bite force (BF) in children with sleep bruxism (SB) during the mixed dentition stage, considering also the occlusal characteristics. The sample was composed by 52 healthy children of both genders, aged 6–10 years. From those, 22 presented signs and symptoms of SB and 30 were the controls. SB diagnosis consisted of both parental report and presence of tooth wear. MP was evaluated by the individual’s ability to comminute an artificial chewable test material for determining the median particle size (X50) and distribution of particles in the different sieves (b). BF was measured using a digital gnathodynamometer with fork strength of 8 mm. The results were submitted to descriptive statistics, Mann–Whitney and chi‐square tests, Spearman’s correlation and multiple logistic regression. Mean BF and X50 did not differ between groups with and without SB. A significant negative correlation was observed between BF and X50 only in the group of children with SB. Moreover, the logistic regression model showed an association between the presence of SB and higher b index. The other independent variables included in the model showed no association with SB. BF did not differ between children with and without SB. Besides, higher BFs in children with SB meant better MP; however, they were more likely to present chewed particles retained in the larger aperture sieves, consequently requiring more chewing cycles to break down the test material in smaller particles.