Of all the cell cycle regulators, cyclin D1 is the most strongly implicated one in oncogenesis. p27 kip1 is a member of the universal CDK inhibitor (CDKI) family and is a putative tumour suppressor gene that appears to play a critical role in the pathogenesis of several human malignancies.This study proved a significant increase in the expression of cyclin D1 from non lesional through perilesional to lesional skin of both malignant {squamous cell carcinoma (SCC) and Basal cell carcinoma (BCC)}and benign skin diseases {psoriasis vulgaris (Ps.V) and verruca vulgaris (VV)} which demonstrates that the effect of cyclin D1 overexpression is restricted to proliferation of cells so they gain a growth advantage.It showed decreased expression of p27 kip1 from non lesional through perilesional hyperplastic to lesional skin of both non melanocytic skin cancer (SCC and BCC) and benign skin diseases (VV and PsV), being significantly higher in lesional skin of benign group compared to malignantgroup. p27 kip1 was proved to be significantly lower in lesional skin of SCC than in BCC and which confirm that its low level indicates poor prognosis and is related to increased tumour progression.