This experiment was carried out at the Vegetable Experimental Farm of the Faculty of Agriculture, Assiut University, Assiut during the two successive winter seasons of 2002-2003 and 2003-2004 to study the effect of five sowing dates ( July 15, Aug. 15, Sept. 15, Oct. 15 and Nov. 15 ) on yield and quality characteristics of broccoli heads of three genotypes under Assiut conditions.Results showed that there were significant differences among the five planting dates. The latest planting date Nov.15 gave the highest value for the duration of harvest period, sulfur % and vitamin C %. There was a consistentsignificant decrease in number of secondary heads with each delay in planting date. Significant differences were also found among the tested cultivars. Assiut -1 cultivar gave the heaviest head weight and the highest value of sulphur % while recorded the lowest value of vitamin C %. . Southern Star cultivar gave the lowest number of secondary head during both seasons and the lowest value of sulphur %..Italyan cultivar had the lowest duration of harvest period and total yield in both seasons but recorded the highest value of vitamin C%.The interaction effect between planting date × cultivar was significant for most of studied traits. Results of this study indicated that Assiut-1 cultivar gave the highest head quality on July, 15 and high sulfur % on Nov.,15. While the Italyan cultivar gave the highest value of vitamin C % on Nov., 15.