A mixture of low grade industrial oils such as acidic crude palm oil (ACPO) and sludge palm oil (SPO) was used for biodiesel production. A novel organic acid, (1R)-(-)-camphor-10-sulfonic acid (10-CSA), was introduced as a catalyst for esterification reaction. 10-CSA shows high activity as a catalyst in the reduction of free fatty acid (FFA) and high conversion of fatty acid methyl ester (FAME). The effects of reaction temperature, reaction time and molar ratio on FFA reduction and FAME conversion were studied. The FFA content was reduced from 8% to less than 1% under optimum conditions. The final product (biodiesel fuel) produced from treated oils (ACPO and SPO) meets international biodiesel standards. This is the first time 10-CSA has been introduced as a catalyst for esterification reaction. This catalyst can treat a wide range of acidic raw materials for biodiesel production. 10-CSA is a promising catalyst and can be used for various chemical reactions. (C) 2014 Elsevier Ltd. All rights reserved.