The present study was designed to quantify dioctyl phthalate (DOP), a bioactive molecule, present in Ehretia laevis from hexane extract, prepared under different conditions. A simple High Performance Thin Layer Chromatographic (HPTLC) method has been developed for the quantification of dioctyl phthalate. The quantification of analytes has been carried out using a mobile phase hexane: ethyl acetate (7:3) on pre-coated aluminium plates (Silica gel Merck 60 F254). Densitometric determination was carried out .The spots were located at 254 nm. The amount of dioctyl phthalate present in the extracts has been estimated by comparing the peak area using the standard sample. Linearity of the standard was found in the concentration range of 3 to 5 μg/spot. The correlation coefficient value was 0.960. The proposed HPTLC method was found to be simple, faster and reliable for quantification of a bioactive molecule, dioctyl phthalate.