 The study aimed to investigate the milling performance of natural fiber reinforced composite materials, specifically JFRP and FFRP composites, by varying spindle speed and feed rate. It was found that increasing spindle speed decreased cutting force and surface roughness while increasing vibration amplitude and delamination factor. On the other hand, increasing feed rate increased cutting force, vibration amplitude, delamination factor, and surface roughness. The most appropriate values for cutting force, delamination factor, and surface roughness were obtained using a WC end mill, but the lowest vibration amplitude was achieved with an HSS end mill. Delamination factors and surface roughness in FFRP composites were higher than those of JFRP composites, while cutting forces of FFRP composites were lower than those of JFRP composites. This article was authored by Jaha Ahmad Selik and Mehmet Sattalp.