There is an interesting in using of medical and aromatic plants or spices as feed additives in fish diets instead of chemical products to avoid side effects and achieve organic aquaculture. Feeding experiment was conduced to evaluate the growth of Nile tilapia fingerlings fed nine diets containing different levels (0, 0.5 or 1%) of dried marjoram leaves (DML), caraway seed meal (CSM), chamomile flowers meal (CFM) and fennel seed meal (FSM) as feed additives. A total number of 270 Nile tilapia fingerlings with an average initial weight (2.5g/fish) were randomly distributed into 27 glass aquaria (70L), in triplicate. Results indicated significant (P 0.05) among all fish groups fed experimental and control diets. It was concluded that, diet containing 1% CSM was economically superior to other tested diets. It saved about 21% of feeding cost per unit fish.