To examine the role of liposomes for the encapsulation of drugs and their suitability for chemotherapy of breast cancer. Pegylated liposomal trans-anethole nanoparticles were synthesized through a reverse-phase evaporation technique. Nanoparticles were characterized in terms of mean diameter, size distribution, zeta potential, encapsulation and drug loading efficiency, drug release pattern and cytotoxicity effects. Size and zeta potential of pegylated nanoliposomal drug and blank pegylated nanoliposomal were 257 nm and -28 mV; 35.7 nm and -21 mV, respectively. Encapsulation and drug loading efficiency were 78 +/- A 2.5 and 2.3 +/- A 4.1 %, respectively. There was a 57 % release of trans-anethole from pegylated liposomal nanoparticles in 48 h. Compared to free drug, toxicological studies indicated around 9- and 8-fold cytotoxicity effect against MCF-7 and T47D cell lines respectively. PEG-liposomes provided a high stability and slow release of trans-anethole in two cancer cell lines.