Oleoresin is a semi-solid mixture of volatile and nonvolatile compounds that can be extracted from plants, herbs, and spices. Red pepper is widely used as a spice in food products and herbal medicine due to the presence of various bioactive substances such as phenolics and flavonoids. The experimental design for oleoresin extraction was done to define the optimum condition that could offer the highest yield of oleoresin. This study aims to optimize the extraction condition for oleoresin from red pepper residues which are the solid waste resulting from essential oil extraction from the red pepper. The optimization for the extraction condition was designed using the Response Surface Methodology with the Central Composite approach, in which extraction temperature (30 to 70 oC) and extraction time (1 to 3 h) played a role as the investigated factors. Using ethanol as the extractant at a solid-to-solvent ratio of 3g to 40 ml of ethanol, the result showed that the extraction temperature and time significantly affected the oleoresin yield. The optimum condition for oleoresin extraction from red pepper residues was obtained at 70 oC and 3 h, providing a yield of 6.38 % (w/w). At this condition, total phenolic and flavonoid contents were found to be 3.74 mg GAE/g, and 6.81 mg QE/g, respectively. The research in this study can be useful information for designing the extraction process and valorization of essential oil by-products.