Introduction: Unsuitable loading on implant causes extreme stress in the bone around the implant and may result in bone resorption. Objectives: This study was carried out to analyze the stress pattern in the bone around the variable thread root form implant of different diameters under axial and non-axial loading. Method: A three-dimensional Finite Element Method was used to study the influence of diameter of an implant on strain and stress distribution design in the cancellous and cortical bone through non-axial and axial loading. Using a computed tomography (CT) a geometric model of posterior mandibular area was created. Two implants of different diameters ie 3.3mm and 3.75mmbut having the same length of 11.5mmwas modelled and embedded in the section of the bone. The vertical load of 100 N and a horizontal load of 50 N from buccolingual and mesiodistal directions were applied on to the abutment. Results: Implant with increased diameter appeared to distribute stress in a more uniform pattern around the implant. Implant with lesser diameter showed high-stress pattern during axial as well as non-axial loading. The highest quantity of stress concentration was detected in the cortical bone regardless of the magnitude and direction of loading. Higher stress was generated in the bone-implant system during non-axial loading. There was the favourable distribution of stress and strain pattern during axial loading. Conclusion: It was concluded that axial loading of an implant appeared to be a favourable direction of loading and does not hamper longevity. © 2021 Elsevier B.V., All rights reserved.