Dental implants provide a major course of treatment for patients who are partially or completely edentulous. These implants are biocompatible metal anchors that are surgically positioned in the jawbone to support the prostheses where natural teeth are missing. However, the use of dental implants has some disadvantages, which can result in complications. Once the clean implant surface is exposed in the oral cavity, it is immediately coated with salivary pellicle and subsequently colonized by oral microbial species. In fact, microbial adhesion and accumulation on implants are considered to play major roles in the pathogenesis of peri-implant mucositis and peri-implantitis. The physico- chemical characteristics of specific material surface are known to significantly influence the bacterial adhesion process. Therefore, the surface characteristics of dental implants have been refined and restructured over a period of time to improve the interaction of implants with host cells and tissues. Hence, investigating the microbiological aspects related to implant surfaces will provide important insights relevant to expectations of treatment outcome. To that end, in this study, we aimed to comparatively evaluate microbial adherence and accumulation on five different types of implants. Specimens were provided by Dental Implant Systems, Biodenta Group and implant surfaces included: .3- .5 μm anodized surface, 1 μm BST surface, .8- 1.0 μm anodized surface, 1.6μm SLA surface and .3- .4 μm machined surface. To assess microbial adherence, the cariogenic bacterial species Streptococcus mutans and the bacterial pathogen Staphylococcus aureus were studied. Results from these studies were analyzed using analysis of variance (ANOVA) and significant differences were further analyzed by Tukey’s Honestly Significant Difference (HSD) test. Pearson’s r was also used to evaluate the association between surface roughness and bacterial accumulation. The present study has demonstrated that not only surface roughness but other physicochemical properties such as surface charge, energy, wettability and biological factors such as host immune response and oral hygiene influence bacterial adhesion and accumulation around implant surfaces.