Facial symmetry is defined by the position, size and shape of points on both sides of face in comparison to the medial and sagittal plane. Mandibular asymmetry plays an important role, aside from impaired aesthetics it can also affect functional problems of the masticatory system. The aim of this study was to investigate the frequency and intensity of skeletal mandibular asymmetry in the mixed dentition and biological predictors of asymmetry. The study was cross-sectional, and the sample consisted of 205 subjects aged 6-15 years. Class II/1 had 59 patients, 77 patients class II/2, and 69 patients had class III. The mandibular asymmetry was estimated from orthopantomogram using Habet`s technique, dental maturity was estimated from orthopantomogram using method of Demirjian and the rotational pattern of facial growth by Jarabak`s ratio from latero-lateral cephalograms. Beside these, there were other recorded parameters such as dental class according to Angle and type of dentition. Analysis results are showing that Class II/1 have accelerated dental maturation in relation to their chronological age. It has been noticed that the subjects of Class II/2 have a significant tendency for horizontal growth pattern. Asymmetries are often present in condylar height rather than the height of ramus, but there was no statistically significant difference between class, gender or type of dentition. When observing Class II/2, stronger intensity of condylar asymmetry can be noticed, while the total height of ramus shows less asymmetry in children with Class II/2 than those with Class III. Multiple logistic regression models show that by controlling other biological predictors, only male gender is a predictor of moderate or significant overall asymmetry. Mandibular asymmetry is more expressed in patients with class III than with class II/1 and II/2 and men. The study has showed no correlation between asymmetry and presumed biological predictors.