The apically repositioned flap procedure, by definition, implies that the mucogingival junction (MGJ) is shifted into an apical location. That this actually would be the case has never been shown in long-term studies. The 13 subjects in the present study had during the years 1964-1965 received treatment of moderately advanced periodontal disease (probing pocket depths less than or equal to 5 mm) in the lower jaw. An apically repositioned flap (ARF) procedure was applied in the left or right half of the mandible and a gingivectomy (GE) was performed in the contralateral side. Starting in December 1981, the patients were recalled for clinical and radiographic determination of long-term results. The width of the band of keratinized gingiva was measured clinically and the distance from the MGJ to the lower border of the mandible (LBM) was measured from orthopantomograms. Slightly less keratinized gingiva was observed on the sides where GE had been used. There was no statistically significant difference in the orthopantomographic distance from the MGJ to the LBM between ARF and GE operations. The results indicate that the apically repositioned flap procedure does not result in a permanent apical shift of the MGJ.