Both types of Diabetes Mellitus (DM) have been linked to impaired bone and soft tissue healing in many studies. Platelet- rich plasma (PRP) is an autologous biological product that has been introduced in many medical aspects as a regenerative agent due to the growth factors contained in platelets, alpha granules. This study was conducted to evaluate the effect of adding (PRP) in a gel form, to the socket of diabetic patients after extraction of a mandibular molar. Twenty adult participants suffering DM type II, were included in the study and equally divided into a study group (I) in which the post-extraction socket received the Platelet gel and a control group (II) in which the post-extraction socket is left to be filled with normal clot, without platelet gel application. The post- extraction sockets of both groups were assessed clinically as well as by Digital radiography, measuring relative bone density at immediate (post-extraction, zero) time, two, four, six and eight weeks intervals. Soft tissue healing evaluated visually showed minor differences between the two groups, meanwhile higher mean percent decrease in bone density in the control group was statistically significant than the study group at the same healing time interval. Bone healing in diabetic sockets is improved by (PRP) application.