Cisplatin is one of the conventional drugs used in chemotherapy which has a potent antitumor function. However, due to the dangerous side effects, including the damage to DNA of the normal cells, its clinical use is limited. The aim of this study was to prepare and characterize nanoliposome containing cisplatin. We optimized liposome formulations through the modification of the proportion of SPC80 (soybeanphospholipids with 75% phosphatidylcholine) and cholesterol content. Then, novel PEGylated liposomal formulations containing SPC80: cholesterol: DSPE-mPEG (at ratios of 85:10:5) were designed and developed to serve as a therapy to achieve more improved pharmaceutical efficiency. Zeta Sizer showed that PEGylated nanoliposomes had a mean diameter of 119.7 ± 2.1 nm, a zeta potential of −26.03 ± 1.34 mV, and entrapment efficiency of 96.65 ± 3%. The optimum formulations represented sustained, thermo-sensitive release, and augmented cellular uptake. The cytotoxic effect of the liposomal drug was higher than the free medication drug that confirmed the efficiency of cellular uptake. This study suggests that nanoliposome-loaded cisplatin plays a vital role in improving drug efficacy and the reduction of dosage. K E Y W O R D Sbreast cancer, chemotherapy, cisplatin, nanoliposome