Facial injury in adults can commonly result in fractures of the mandible. Autologous mesenchymal stem cells (AMSCs) transplantation is proposed as an alternative to conventional graft treatment to improve bone regeneration. The aim was to evaluate the effectiveness of AMSCs application in mandibular fractures to reduce regeneration time and increase bone quality. This study was a single-blind controlled clinical trial conducted in patients with mandibular angle fractures. Patients were divided into two groups: study group fracture reduction plus application of AMSCs and control group only fracture reduction. AMSCs were obtained from adipose tissue 24 h before the procedure. Intensity and density were evaluated in normal bone and fractured bone at 4 and 12 weeks after surgery using panoramic radiography and computed tomography. A total of 20 patients, 10 in each group, were included. The study group had a mean age of 31.2 ± 6.3 years, and the control group mean age was 29.7 ± 7.2 years. All patients were male. Bone quality measured in grey levels at week 4 was 108.82 ± 3.4 vs 93.92 ± 2.6 (P = 0.000) using panoramic radiography and 123 ± 4.53 vs 99.72 ± 5.72 (P = 0.000) using computed tomography. At week 12, the measurements were 153.53 ± 1.83 vs 101.81 ± 4.83 (P = 0.000) using panoramic radiography and 165.4 ± 4.2 vs 112.9 ± 2.0 (P = 0.000) using tomography in the study and control groups, respectively. Similar ossification values were obtained after 4 weeks when the use of AMSCs was compared to simple fracture reduction. However, after 12 weeks, the AMSCs group had a 36.48% higher ossification rate. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.