The aim of this work was to examine the degree and direction of asymmetry in the condyle path, and its associations with facial and dental midline asymmetry in patients with treated and untreated unilateral cross-bite. The subjects were 22 patients, 16 female and 6 male, aged from 9 to 50 years. Nine patients had a history of treated unilateral cross-bite, the mean age of this group being 11.1 years. The children had been treated with removable or fixed expansion appliances at an age of 5-8 years. Thirteen patients had untreated unilateral cross-bite, their mean age being 23.4 years. The clinical examinations were performed by two orthodontists and standard PA roentgenograms were taken in a cephalostat. The condyle path was recorded from the inversion of a face bow fixed rigidly on the anterior mandibular teeth, the positions of the bow being first recorded with the teeth in maximal intercuspation and then in protrusion with the midline unchanged. The condyle path was found to be asymmetric in both the treated and untreated lateral cross-bite groups and to be steeper on the side of the diagnosed or treated cross-bite. The degree of asymmetry was found to be twice as great in the untreated as in the treated group. The facial asymmetry parameters describing the position of the mandible showed the strongest correlation with condyle path asymmetry. The results stress the importance of early treatment of lateral cross-bites.