Ethylene gas can be applied to oil palm fresh fruit bunches (FFB) to enhance fruit detachment and produce fresh loose fruits (LF) that could be processed separately to reduce oil loss due to empty fruit bunch (EFB) absorption during the milling process. Response surface methodology (RSM) with central composite design (CCD) was employed to achieve optimum fruit detachment in oil palm FFB as the main response with two experimental variables, which were ethylene concentration (500 to 2000 ppm) and incubation period (18 to 24 hr). The proposed model showed an R2 value of 0.85 where the experimental variables were significant to the result. From the model, 26% of the targeted fruit detachment was attained with ethylene concentration of 1102.7 ppm and an incubation period of 21.5 hr. The application of optimum ethylene gas and incubation time from the study can be then tested on a pilot scale to reduce optimisation time.