We aimed to find the effect of caffeic acid phenethyl ester (CAPE) on the expression profiles of cell cycle control genes in breast cancer cell line (MCF-7). The cytotoxic effect of CAPE on MCF-7 cell line was found with an XTT analysis. Total RNA was isolated from the cells exposed to IC50 dose and untreated control cells. Expressions of genes related to cell cycle control (CCND2, RB1, ATM, CDC34, CDK5RAP1) were evaluated by qRT-PCR by the LightCycler 480 System (Roche). GAPDH and ACTB housekeeping genes were used for the normalization of gene expressions. IC50 value of CAPE in MCF-7 cells was calculated as 75 mu M. It was shown that IC50 dose of CAPE induced significant upregulation in expressions of cell cycle control genes, compared to control cells. CAPE increases the expression of genes that are important in cell cycle control, suggesting that this component can be used as an effective chemopreventive agent in breast cancer cells.