This research paper describes the generation of poly(ethylene terephthalate) (PET)/organoclay nanocomposite filaments by melt-spinning method and investigation of their physical and dyeing properties. Two montmorillonite types of clay were modified using an intercalating agent synthesized and PET/organoclay (85/15 wt/wt) master batches were prepared using a corotating intermeshing twin screw extruder. Afterward, nanocomposite filaments containing different amounts of organoclay (0.55 wt%) were produced and dyed with two disperse dyes at atmospheric and high temperature dyeing conditions. Increased clay concentration led to reduced mechanical properties. Nonetheless, PET/organoclay nanocomposite filaments showed enhanced dyeability. POLYM. ENG. SCI., 2013. (c) Society of Plastics Engineers