EGYPTIAN olive clones 'Sewia', 'Maraki' and 'E52' were ……compared with two international cultivars 'Coratina' and 'Koroneiki' during two seasons (2011 and 2012) at olive collection farm located at Cairo- Alexandria desert Road . Results showed that, time of flowering varied according to cultivars and season. 'Coratina', 'Maraki' and 'Sewia' were earlier than 'Koroneiki', but it was late for E52. 'Coratina' had longer inflorescence (>3.5 cm) than the other cultivars which were medium (2.5-3.5 cm). The highest number of flowers per inflorescence (> 25) was recorded for 'Maraki' and the lowest number (<18) was recorded for 'Koroneiki'. Perfect flower percentage varied according to cultivars and to climate. It was the highest in 'Coratina' (>90%) and the lowest in 'Sewia' (75%). Fertility of pollen was highest in 'Sewia' and the lowest in 'E52'. All of the studied cultivars were self-incompatible. Under open pollination 'Coratina' produced the highest yield in the two seasons; 'E52' was alternate bearing cultivar. Fruit and stone weight were the lowest in 'Koroneiki', medium in 'E52', high in 'Coratina' and 'Maraki', and very high in 'Sewia'. Fruit shape was elongated in 'Koroneiki', 'ovoid-elongated' in 'E52' and 'Coratina', and ovoid in 'Sewia'. Stone shape was elongated in 'Koroneiki', 'E52' and 'Coratina'; oviod in 'Maraki' and 'elliptic' in 'Sewia'. Oil content (%) was the highest in 'Maraki' and 'E52', followed by 'Coratina', 'Sewia' then 'Koroneiki' in decreasing order. Based on the quality parameters of the oil (acid value, peroxide value, UV absorption at 232 and 270 nm, polyphenols and tocopherol) provided that it ranked extra virgin. The ratio of total unsaturated to saturated fatty acids was the highest in 'Maraki', followed by 'Sewia' then 'Coratina', but the lowest ratio was found in 'E52' and 'Koroneiki'. Based on RAPD and ISSR-PCR genetic markers, the genetic similarity was between 'Sweia' and 'Maraki' and the least between 'Coratina' and 'Koroneiki'.