The present work relates to the occurrence of fibre rupture during fibre separation in rotor spinning and also discusses the mechanism of such rupture. The reduction in fibre length during opening has been studied at different span lengths. A correlation has been drawn showing the influence of combing roller action on yam tenacity and elongation. Fibre rupture has direct relationship with opening roller speed. Fibre rupture and surface damage occurring due to action of opening roller together are found to mar the yarn quality index.