Dental calcification is a biological phenomenon used to estimate the maturation status of growing children. The effect of body mass index percentile (BMI-percentile) on this process appears contentious among researchers. To determine the predictive effect of body mass percentile on mandibular canine calcification. A prospective descriptive cross-sectional study. This was a prospective cross sectional descriptive study comprising of eighty four participants (5-17 years) who visited the Child Health Dental Clinic of Federal Medical Centre, Keffi, Nigeria between January and September, 2021. Mandibular canine calcifications of the study participants were staged using the Demirjian method while the World Health Organisation growth chart specific for age and gender was used to classify the BMI-percentile. The effect of BMI-percentile on the mandibular canine calcifications was determined using multinomial logistic regression. Chronological age had a significant predictive effect on the mandibular canine calcification (P=0.002) as against gender and BMI-percentile. A one-percentile increase in the BMI-percentile increases the likelihood of healthy children of having to present in stage D by 3.454 compared to obese children, but this effect was not statistically significant (P= 1.000). Obese children have a tendency of having advanced mandibular canine calcification than healthy children. Female participants were likely to be in advanced mandibular canine calcification stage. Early intervention is therefore suggested for obese children.