The main aim of the present work is theoretical studies and docking analysis on the novel small molecule irilone as a progesterone receptor (PR) effect supporter in endometrial and ovarian cancer cell lines. The quantum mechanical computations are done using B3LYP/6-31+G(d,p) level of theory on the molecule under study at room temperature. The theoretical calculations showed that irilone is a stable small molecule with high electrophilicity property. The density of states (DOS) graph indicated that the virtual orbitals of the said compound have more density than the occupied orbitals. These studied indicated that the title compound can make a complex with progesterone receptor (PR) using steric and hydrogen bond (HB) interactions. The docking analysis showed that the receptor (PR-B isoform) residues Pro-696, Gln-725, Met-759, Arg-766, Glu-695, Asp-697, Leu-758, Lys-822, Ile-699, Val-698 and Trp-755 play main role in receptor-ligand complex formation.