The aim of the present study was to evaluate the influence of recombinant platelet derived growth factor-BB (rhPDGF-BB) on the cellular proliferation, morphology and adherence of human periodontal ligament fibroblasts (PLFs) to the root surfaces of periodontally diseased and healthy human teeth roots at two different time periods. Primary cell cultures of PLFs were obtained from clinically healthy premolar or mandibular third molar teeth. 11 scaffolds were prepared from healthy teeth for group-1 (Healthy Substrates), 33 scaffolds were prepared from periodontally diseased teeth, which were further divided in Group-2 - Periodontally diseased substrates, Group-3 - Scaled and Root planed (SRP) substrates, Group-4 - SRP + rhPDGF-BB (50 ng/ml). Groups were further subdivided into two groups (n = 5 scaffolds per subgroup) and PLFs were incubated on the scaffolds for three and seven days, topographical assessment was done on the remaining substrate. Cell morphology and counting was assessed under a scanning electron microscope at 350× on day three and seven and statistically compared with the Mann-Whitney U test and the Kruskal-Wallis test. On day three, Group 1 showed least number of cells attached, whereas maximum number of cells were attached on Group 3 (SRP only) substrates. For day 7, Group 1 and Group 4 showed increase in the number of cells from day 3 to 7, while number of cells attached/substrate reduced drastically for Group 2 and 3 substrates. Group 3 and 4 showed better adhesion and proliferation of PLFs as compared to Group 1 and 2. Group-1 and Group-4 showed predominantly spindle cells with flat appearance, Group-3 showed stellate cells and Group-2 showed predominantly distorted spindle shaped cells. The results of this in-vitro study indicates that rhPDGF-BB plays a significant role as an adjunct to periodontal therapy in influencing maturity, attachment and proliferation of PLFs.