Abstract: This research was conducted with the main purpose to evaluate the level of genetic similarities among an olive population situated in Djebel Ouslet (central east of Tunisia). Morphological characters and phenological growth stages of four olive cultivars Ousleti, Brahmi, Chaibi and Jeli were described during 2004-2006. Morphological classification used, was based on tree, leaf, inflorescence, fruit and endocarp characteristics. Technological characters of the fruits concerned the oil content and their chemical composition. Floral phenology, flowering and pistil abortion rates of the cultivars were recorded at full bloom. Also, a pollen monitoring survey for each cultivar was investigated. This study shows the relative differences between cultivars in flowering, fruiting patterns, oil yield and fatty acid contents of the fruits. Under the conditions of Djebel Ouslet, the flowering period of the cultivars was similar and covered each other but little differences were recorded in the duration and the onset of flowering. The evaluation of self-fertility showed that all cultivars can be considered self-compatible and fruiting rates were higher under free-pollination than under self-pollination. The results obtained are consistent with the high pollen capacity of the cultivars, suggesting their use as pollinizers in the cross-pollination assays to improve productivity. Large differences in oil content and in fatty acid profiles were observed in the cultivars examined. But their olive oil are conform to international standards. The ranges of fatty acid for all the cultivars fall within the accepted limits for fatty acid composition of Virgin olive oil. This database of the most representative cultivars grown in Djebel Ouslet concerning their agronomic and chemical characteristics could be exploited for screening synonyms within this olive population and could provide information for cultural purposes and breeding programs.