The present work has been done to study more closely the possi­bility of producing commercially accepted rotor yarns spun from waste and low quality cottons to give spinning value to the waste and low grade cottons. The influence of cotton type i.e. comber noils, export type, wati makhlout and two ordinary cottons 'Giza 80 and Giza85⁴ and yarn count 20Ne (29.5 tex), 25 Ne (23.6 tex), 30Ne (19.7 tex) and 35 Ne (16.8 tex) with two twist multipliers 3.8 (36) and 4.2 (40) on the properties of open-end rotor spun yarn has been studied. The multiple regression analy­sis indicated that the Short Fiber Index, Micronaire reading and Fiber strength showed the greatest influence upon Open-End yarn strength. It was found that the open-end rotor spinning offers the opportunity for vi­able spinning of cotton wastes (comber noils) and low quality cottons (Wati Makhlout and export type) prepared in a recycling process for end uses with adequate yarn quality.