The replacement of lost teeth with endosseous implants is an effective and acceptable treatment modality. Oral implants play an important role for replacing missing teeth to restore the function and aesthetics. They have proven to be a successfully predictable treatment modality, and their osseointegration occurs with a high success rate. The aim of this study was to evaluate the role of different lengths and diameters in osseointegration process of delayed dental implants. Thirty six patients indicated for insertion of dental implants were included in this study. The patients were evaluated both clinically and radiographically immediately, and at 1, 3 and 6 months post-operatively after loading. The clinical parameters included the sulcus depth around the implant, mobility of implant and gingival index. The bone density measurements around the implants were carried out via direct digital radiography.The results of this study showed clinical success of all cases reflected by gradual decrease in the sulcus depth, absence of implant mobility and presence of normal mucosa. The bone density measurements were increased throughout the time interval after loading and reached its peak at six months postoperatively following the normal sequence of implant healing. It was higher in group ΙΙΙ (D: 3.9) and in length (13mm) than that of other groups at all time interval indicating increase in osteointegration with the increase of both width and length of the implants. Also, increase of the implant length was found to be more significant than its width.In conclusion, in the present study, osteointegration around endo-osseous implant follows the normal sequences of healing with all length and widths and this finding confirmed by both clinical and quantitative density measurement at follow up period. The success rate was 100% because we fulfill all the factors which help in success of the osteointegration process. The use of longer and wider implants may enhance bone formation around them taken in considerations space availability, the presence of vital structures and the amount of the supporting bone. Delayed implants are considered a reliable technique provides a successful osseointegration.Further extension of this work is needed to assess the long term effect of different lengths and diameters of the implant on osteointegration, stability and success rates of the implants.