Aims:The majority of human breast tumors are estrogen receptor α (ERα) positive. However, not all of the ERα+ breast cancers respond to anti-estrogens drugs for those women who do respond, initial positive responses can be of short duration. Thus, more effective drugs are needed to enhance the efficacy of anti-estrogens drugs or to be used separately in a period of time. In view of potential cytotoxicity associated with silybin as polyhydroxy compounds a synthetic 4-hydroxychalcones (bis-phenol) was considered to explore its anti-carcinogenic effects in comparison to silybin on ERα+ breast cancer cell line. Methodology: We have studied the inhibitory effect of 4,4'-dihydroxychalcone on the T47D breast cancer cell line by MTT test and the IC 50 s were estimated using Pharm PCS. Results: The 4,4'-dihydroxychalcone showed significant dose-and time-dependent cell growth inhibitory effects on T47D breast cancer cells. The IC 50 of 4,4'-dihydroxychalcone on T47D cells after 24 and 48 hours was 160.88+/-1 µM, 62.20+/-1 µM and for silybin was 373.42+/-1 µM,176.98+/-1 µM respectively.