The present investigation was conducted at the Faculty of Agric. Cairo Univ. Giza, Egypt during the two successive seasons of 2012 and 2013 to study the effect of foliar application of yeast natural extract at 2, 4, 8 and 12 g/L on the growth, flowering, yield and certain anatomical structure of marigoldstem and leaf. Results indicated that all studied traits of growth, flowering and yield well improved due to yeast extract application at the levels of 2, 4 and 8 g/L, whereas decreased at 12 g/L. The maximum increment was detected at 4 g/L due to its positive effect on the anatomical structure of stem and leaf.