Correlation of pleural fluid cholesterol level with light’s criteria to differentiate exudate from transudate pleural effusion. Classification of transudate and exudate clinically was done independently based on the light's criteria. Pleural fluid cholesterol levels of 100 selected patients were obtained. The cholesterol levels were compared with the earlier obtained data to study its specificity and sensitivity in differentiating exudate from transudate effusion. It was found that pleural fluid cholesterol in comparison to protein values in differentiating exudate from transudate showed a sensitivity of 79.55%, specificity of 91.07%, the positive predictive value of 87.50%, the negative predictive value of 85.00%, with a P-value of <0.001. Comparison of pleural fluid cholesterol with LDH values showed a sensitivity of 86.36% specificity of 94.64%, the positive predictive value of 92.68%, the negative predictive value of 89.83%, with a P-value of <0.001. Also, a comparison of pleural fluid cholesterol to light's criteria showed a sensitivity of 100% and 86.4% in the transudative group and sensitivity of 100% and 91.1 % in the exudative group, respectively. Routine measurement of pleural fluid cholesterol may serve as a valuable diagnostic indicator for differentiating exudate from transudate effusion.