Objective: In this work, sodium lauryl sulfate (SLS) was used to present a simple spectrophotometry approach to more accuratequantification of fenofibrate (FENO) concentration in five natural oils (soybean oil, lemon oil, black seed oil, cardamom oil, and garlicoil). In the published work either organic solvent was used which may result in false results due to the dissolving of oil by organicsolvent, or high-performance liquid chromatography (HPLC) was utilized, which is a sophisticated instrument that may not be availableat every research facility.Methods: construction of a calibration curve using a series of FENO concentrations added to 0.5% SLS phosphate buffer solution andmeasuring the absorbance by spectroscopy at 289 nm. The drug samples in different oils were diluted with 0.5% SLS phosphate buffersolution prior to direct reading by spectroscopy. According to the International Conference on Harmonization requirements, the methodwas validated regarding specificity, precision, accuracy, and determination range.Results: FENO gave absorbance maxima at 289 nm in 0.5% SLS solution, the beer’s law was obeyed in the range of 0.0125 to 0.05mg/ml. High linearity (in the scope of 10 - 125 mg, R2=1), highly specific, good accuracy (95- 104), precision (SD< 10%), and a widerange of detection, indicate validation of the procedure.Conclusion: the proposed method for FENO analysis is simple, fast, and promising for easy determination of FENO in bulk andpharmaceuticals.