Polyester fabrics are conventionally dyed mainly at either high temperature and high pressure or normal pressure using a toxic carrier. These harsh method not only energy consuming but as well affects the environment severely. Thus, for cleaner production and with an eye on energy saving, a green and ecological viable and sustainable continuous dyeing process were developed for polyester fabrics using aqueous polyethylene glycol (PEG). Polyester fabrics were dyed with CI Disperse Blue 56 in a continuous process by padding the fabric in an aqueous solution of PEG10000 with 100% pick-up. Different factors that may affect the dyeability of polyester fabrics, such as PEG water ratio, drying time and method, curing temperature and time, were investigated. The selected conditions obtained were applied using four disperse dyes; namely, CI Disperse Blue 56, CI Disperse Red 50, CI Disperse Red 343, and CI Disperse Orange 29. A tentative mechanism is suggested for the role of PEG10000 in the dyeability of polyester fabrics that relies on nanodispersed dye together its action as a fiber plasticizer and swelling agent. The excellent color data, levelling and fastness properties of the dyed fabrics using this facile method suggest its potential as a viable and ecological alternative for carrier-atmospheric dyeing and high-temperature dyeing of polyester fabrics with great potential for application to a broad range of synthetic fibers.