A pot experiment was conducted during the growing seasons 2013/2014  and 2014/2015 at The Experimental Farm and laboratories of the Agricultural Botany Department, Faculty of Agriculture, Mansoura University to study the effects of yeast extract either at 0, 4 or 8 gL^-1 on key primary and secondary metabolites of Catharanthusroseus, cultivars cv. rosea and cv. alba. Results indicated that total alkaloids, total soluble phenols and flavonoids were significantly higher in cvrosea compared with cvalba. Applicationof yeast extract (YE), generally, enhanced the accumulation of alkaloids, phenols and flavonoids. In addition, treatment with YE increased the concentration of kinetin, indole acetic acid, gibberellic acid and benzyladenine whereas decreased that of abscisic acid. Moreover, the concentration of the essential elements N, P, K, Ca and Mg were higher in YE-treated plants, and, the effect of the higher level was more effetine. It was concluded that YE could be utilized as an elicitor to enhance the accumulation of the medicinally-important secondary metabolites in C. roseus plants.