Objective : Silibinin is an antioxidant agent and is shown to have anticancer effects in different cancers including lung, breast, colorectal, liver, prostate, and kidney. There are challenges in the clinical use of Silibinin. The main limitation is low solubility, poor oral absorption, and extensive hepatic metabolism. We developed a High-Performance Liquid Chromatography sensitive method for quantification of Silibinin in in-vitro samples to quantify in different formulations. We applied HPLC set, C18 column as stationary phase and the mixture of methanol (90%) and water (10%) as mobile phase. Utilized solutions were daily prepared through serial dilution of stock solution to make specific concentrations ranged between 10 μg/ml to 100 μg/ml. The developed method was validated by credible guidelines.Results : The calibration curve was drawn according to the height peaks of different concentrations and the established method demonstrated a linear ranged from 10 to 100 µg/ml, with a correlation coefficient of 0.996 for in-vitro samples. The retention time was 2.97 min, and the accuracy and precision (inter-day and intra-day) of the developed method was in the range of 88-105.9%. These results demonstrate that the developed method can be a fast and accurate method for quantification of Silibinin in in-vitro samples.