Similar seed cotton samples representing the Giza 80 Egyptian cotton variety were ginned using a conventional reciprocating-knife gin-stand and modem rotary-knife gin-stand sequences in three replications. Samples from ginned lint were tested to evaluate the differences in fiber properties and yam manufacturing performance resulted from using the two techniques in ginning. Regarding to waste losses, total blow-room and carding waste values were 9.5% and 4.8% for both lint ginned on reciprocating and rotary knife gin-stand, respectively. The low blow-room and carding waste in the rotary gin-stand can be related to its low ginning out-turn, while high ginning out-turn in reciprocating gin include high blow-room and carding waste due to absence of seed-cotton and lint cleaners. It is worthy to mention that as seed cotton and lint cleaning takes place in rotary-knife ginning plant, the removal of impurities, is usually accompanied by shortening of the length distribution. In practice, the trash content of lint cotton is a major concern for, mainly, spinning mills. Therefore, it is important to conclude that the rotary gin-stand reduce the trash content, impurities and short fibers, high productivity, which resulted in maintenance of the fiber and yarn quality in spite of reducing the ginning out-turn. Hence, it is preferable to redraw the policy of ginning in Egypt to development the ginneries sector with rotary gins equipped with seed-cotton and lint cleaners.