This study was carried out in Kom Hamada Spinning and Weaving Company, and Cotton research Institute, to assess the quality of Giza 90, the new promising long-staple Egyptian cotton variety. The goal of new variety introduction is to replace a current variety with one that shows significant improvement in particular areas, notably yield, fiber quality, resistance to relevant diseases or pests. From the breeding per­spective, new varieties should always be 'available". From textile and commercial perspective, availability will depend on the probable profit potential of a new variety. Giza 90 was produced to meet these require­ments and may replace Giza 83. The three long-staple Egyptian cottons; the commercially grown Giza 80, and Giza 83 and the newly introduced Giza 90 were spun into 20s and 30s counts on both ring and rotor spinning systems. Yarn quali­ty parameters were determined. Giza 90 was found to be generally bet­ter to Giza 83 in single yarn strength, yarn unevenness, yarn neppiness and yarn hairiness. However, as coarseness is required and preferred by many mills, Giza 90 could be regarded as comparable to Giza 80 and to be grown commercially so as to suffice the requirements of as many mills as possible. Compared to ring yarns, rotor yarn of the three varie­ties possessed lower strength. This strength loss was, however, partially compensated by a lower hairiness and greater evenness of the rotor yarns.