Anastrozole (ANZ) is a potent non-steroidal aromatase II inhibitor (AI) used to decrease or delay the progression of breast tumor growth in some women. Since ANZ could be delivered transdermally due to its physicochemical characteristics as (log p of 3.5, aqueous solubility of 0.5 mg /mL, low dosage and half-life of 46.8 hr.)   so, it could be used as a modelling drug evaluation of ethosomes, the current study aimed to formulate ANZ loaded ethosomes and evaluate the formulated ethosomes for particle size and PDI, entrapment efficiency and in vitro release profile. Film hydration method was used to prepare ANZ-loaded ethosoms. using different ratios of phospholipid (Soy phosphatidyl choline) and ethanol at variables probe sonication energy and time ratios.  polydispersity index and particle size were used to evaluate the prepared ANZ-loaded ethosoms. The optimized formula of ethosomes which contain (1% Soy phosphatidyl choline,20% ethanol subjected to 300watt sonication energy with 1/3 sonication on /off ratio) was studied for in vitro drug release. It had 127.75±0.36 nm particle diameter and 74.7136 ± 3.457 % entrapment efficiency, the release kinetics obey Korsmeyer-Peppas and non-Fickian release as R2=0.9779 and n=0.737.  The ratios of Soy phosphatidyl choline, ethanol, sonication energy and duration had a significant impact on the particle size of ethosomes at (p0.05). The preformulating analysis of Powder X-ray diffraction (P-XRD) indicate amorphous ethosomes. Fourier transform infrared (FTIR) showed the inertness among components.