Abstract: Linoleic Acid (LA) from a mixture of free fatty acids obtained from local Jatropha curcas seed oil was separated using urea complex fractionation. In this study, variations of factors that affect the urea complex fractionation such as the ratio of urea to free fatty acid, crystallization temperature and crystallization time were examined to obtain optimum condition using response surface method (D-optimal design). Under the optimal conditions, the percentage of LA was 92.81 and the percentage of yield of NUCF 7.8 at urea/FFA ratio (w/w) 5, a crystallization temperature of -10°C and a crystallization time 24 h. This showed that the experimental conditions should be suitable for the preparation of high purity LA. Performing the experiment at this condition gave results that were close to the predicted values.