Platelet-rich plasma was initially introduced by Choukroun in 2000 as an autologous blood concentrate prepared through centrifugation with applications in oral surgery.1 Today, applications of PRF include soft tissue grafting, ridge preservation, bone grafting, and sinus lift procedures, with significant benefits shown in wound healing, clinical outcomes, and material handling.2-5 Leukocyte-PRF (L-PRF) is defined as centrifugation of autologous blood at 2700rpm for 12 minutes.21 Investigations have shown L-PRF to release greater concentrations of specific growth factors, namely PDGF-BB, TGFb-1, VEGF, which play a role in angiogenesis, wound closure, and immune function, and were selected for evaluation in this study.8-11; 15; 27-32 There have been no previous studies analyzing the effects of cigarette-smoking on the content of growth factors in L-PRF. Smoking as a proven periodontal risk factor shows harmful effects on wound healing, immune function, and regenerative capabilities in periodontal surgeries.16-20; 22-26 The aim of this case control pilot study was to compare possible differences in growth factor concentrations in L-PRF samples obtained from cigarette-smokers versus those from non-smoker healthy individuals. Three 10ml glass tubes of autologous blood were collected per patient in a pool of five healthy non-smoking patients and four current smokers. Analysis through enzyme-linked immunosorbent assays (ELISA) showed statistically significant differences (increases) in growth factor concentrations for PDGF-BB and VEGF in smokers compared to healthy nonsmoker controls. TGFb-1 levels were not in a detectable range. These results suggest a possible benefit to applying L-PRF for periodontal surgery in patients who are smokers.