Background: Dental implant survival is initially dependent on successful osseointegration following placement. Any alteration of this biological process by excessive surgical trauma, infection, or metabolic upset may adversely affect treatment outcomes. Material and method: This study was undertaken to assess the effect of smoking and diabetes on prognosis of dental implants. A total of 60 patients were enrolled in this study. The patients were categorised into four groups: Group 1: 15 patients who were non-diabetics but were chronic smokers, Group 2: 15 patients who were diabetics but were non smokers, Group 3: 15 patients who were diabetics and were also chronic smokers, Group 4: 15 patients who were non-diabetics and non smokers. All the demographic details of the patients were recorded. The patients were evaluated every month for a duration of 6 months after implant loading to check for signs of bone loss and implant failure. Preoperative and follow up radiographs were collected and compared. Results: In the current study 29 patients were below 35 years of age whereas 31 patients were above 35 years of age. Out of 60 patients 34 were males and the rest 26 were females. Out of 15 cases of implants in group 1, there was failure in 4 cases. Number of cases of implant failures in group 2, 3 and 4 were 3, 6 and 1 respectively. In the current study the statistical analysis showed that difference in the success rate of implants was statistically significant between groups 1 and 3, group 1 and 4, group 2 and 3, group 3 and 4 with P-values of 0.00, 0.01, 0.02, 0.00 respectively. However the results were not significant between the groups 1 and 2, groups 2 and 4 with P-values of 0.86, and 0.58 respectively. Conclusion: Both smoking and diabetes influence the prognosis of dental implants and the presence of anyone of the above has detrimental effects on the success of implants. Keywords: Bone, dental implants, Osseointegration, smoking, diabetes.