Aim: The aim of the study was to study the maxillary tissue changes under complete dentures opposing mandibular implant-supported overdenture retained by either two or single midline implant. Material and Methods: Fourteen completely edentulous patients were chosen for this study. Patients were randomly divided into two groups: Group I; Seven patients received mandibular overdenture retained with 2 implants in the canine region bilaterally with ball and socket attachment. Group II; Seven patients received mandibular overdenture retained with single implant in the midline with ball and socket attachment. Clinical and radiographic evaluations were done by measuring the thickness of the soft tissue overlying the anterior maxillary ridge and amount of bone resorption respectively, measured at 2 points 1 cm and 2 cm bilaterally to the midline at time of implant loading, 3, 6, 9 and at 12 months. Results: there was non-significant increase in maxillary mucosa thickness in both groups at both points of measurements. Also, there were posterior radiographic bony changes in maxillary ridge within both groups. There was significant increase in maxillary bony changes in Group II in comparison to Group I. Conclusion: Within the limitations of this study, it was concluded that there was slight increase in the soft tissue thickness overlying the anterior maxillary ridge in each group. But there was slight increase in Group II more than Group I. More bone resorption in posterior region of maxilla was observed in Group II patients.