In this study Investigation of effects of sildenafil citrate on some of the hematological parameters in the early phase of wound healing in diabetic rats was aimed in this study. Total 30 rats were used in the study. Rats were divided into three groups equal in number (control-non diabetic, diabetic and diabetic+Sc). While no treatment was given to the control-non diabetic and diabetic groups, sildenafil citrate was given to the diabetic+Sc group intraperitoneally with a dosage of 0.7 mg/kg/day dosage for 3 days after creating wounds: under ketamine anesthesia, a circular, full thickness, standard wound was created on the back of each rat by using a 0.8 cm sterile punch. Cardiac blood was drawn in tubes containing EDTA from each group before the creation of wounds and on days 1, 2 and 3 following the creation of wounds. Differential leukocyte counts were determined in blood samples containing anticoagulant. For this purpose, blood smears were prepared from blood samples and stained with Giemsa method. It was found that, while neutrophil counts increased in all the groups during the wound-healing periods with the increasing number of days, lymphocyte counts reduced and in control and Sc+diabetic groups, monocyte counts increased. As a result, it was concluded that Sc plays an important role in eliminating the pressure on the cellular activities in the early period of wound healing and continuance of the inflammatory process and wound healing within normal limits and also that this could be demonstrated with hematological analyses. © 2011 Academic Journals Inc.