Two field experiments were conducted in a sandy soil at a private farm at North Sinai region during 200/2004 and 2004/2005 seasons to study the effect of three planting dates (15/8, 15/9 and 15/10) and three harvesting dates (175, 190 and 205 days after planting) on yield and quality of six sugar beet cultivars (Pamela, Hipoly2, Reno, Monte Bianco, Oscar poly and Gloria). Planting dates significantly affected sucrose and purity percentages, as well as, root and sugar yields/fed. in both seasons. The highest root and sugar yield were obtained from the 15m Sept. planting. Harvesting after 205 days from planting recorded the highest root weight, sucrose and purity percentages as well as root and sugar ylelds/fed. Sugar beet cultivars differed significantly in all traits under study. Oscar poly variety recorded the highest root yield but, Monte Bianco cultivar surpassed all cultivars in sugar yield. The Interaction between each two factors under study was insignificant. The response equation of root yield/fed to delaying harvest showed diminishing returns. A higher predicted root yield than that retained herein, could have been obtained if harvest was delayed beyond 205 days after planting.