Olive oil was laboratorial extracted by pressure system from olive fruit variety Koroneiki by using different concentration of sodium chloride (NaCl) during malaxation step. Using 2% NaCl was the best concentration where it enhanced oil extraction, improved the quality of the resultant oil as well as increased oil stability. The resultant olive oil was used in preparing of cheese yoghurt. Fermented buffalo milk (after adding the starter) was divided into three portions, the first portion serve as control while, the second and third part was fortified with 1 and 2% (w/w) of the extracted olive oil, respectively. The three portions were manufactured cheese yoghurt by the traditional method. Results revealed that samples manufactured by 1% olive oil gained the highest sensory scores, they possessed good flavor, acceptable body and texture and favorite appearance. These properties were gradually decreased with the progress of storage (after 2 weeks) to reach the minimum scores at the end of storage. Generally, the values of pH decreased during cold storage until 3 weeks; whereas, TS, TP increased in all treatments and TVFAs took the same trend. Acetaldehyde and diacetyl contents were also increased until 2 weeks then they began to decrease until the end of storage (3 weeks) in all treatments. Total viable count and lactic acid bacteria were gradually increased during storage at 5±1°C till the first week then it decreased through the remaining period of storage (2 weeks). Control and treatments behaved the same trend. Yeast and molds were not detected throughout storage. All samples were free of coliforms. So, It could be concluded that using of olive oil in preparing cheese yoghurt did not clearly affected the chemical and microbiological properties of the resultant product; however a noticeable improvement in the sensory properties was observed when used 1% olive oil.