Objective: the present study was undertaken to estimate the effect of either platelet-rich plasma (PRP) or PRP with stem cells on orthodontic mini-implants osseointegration. Materials and Methods:  Nine mature dogs classified into three groups were control, PRP group, and PRP with stem cells group, respectively. MSCs were isolated from dog's adipose tissue and cultured for 3 weeks before implantation. A total of twenty-seven self-drilling mini-implants were used. Two mini-implants were inserted in the right femur of each dog (one for a control group and second for PRP group). Moreover, one mini-implant was inserted in the left femur of each dog in PRP with ADSCs group. The implants were examined by histological and digital morphometric analysis on 1, 2, and 4 weeks after implantation. Results: Our data indicate that PRP with ADSCs treatment resulted in increased bone formation around mini-implants compared to the control and PRP groups. Conclusion: Our findings strongly suggest that bone tissue-engineering may be sufficient for accelerating and increasing bone formation around mini-implant during orthodontic treatment. Key words: platelet rich plasma (PRP), mesenchymal stem cells (MSCs), mini-implants, osseointegration, tissue-engineering