Arid regions in Egypt are characterized by poor nutrients such as macro and microelements and unfavorable environmental conditions which negatively affect growth and productivity of medicinal and aromatic plants including anise (Pimpinella anisum L.), coriander (Coriandrum sativum L.) and sweet fennel (Foeniculum vulgare var. Dolce) plants. Thus, the main objective of the present investigation was to study the effect of different levels of NP fertilizers, trace elements and their interactions on the morphological and biochemical contents of these three plants under arid regions conditions. The effects of NP and trace elements on the growth (height, leaf number, branch number, umbel number, fresh weight, dry weight and fruit yield per plant) was measured and quantitative analysis of essential oils, fixed oil, total carbohydrates, soluble sugars and nutrient content of anise, coriander and sweet fennel were performed. The most effective rate was N3P3 x trace elements interaction, resulting in a positive increase in vegetative growth characters. The highest values of vegetative growth characters were 53.4, 45.9, 10.3, 33.5, 36.8, 11.8 and 7.9, respectively for anise; 83.0, 69.3, 9.8, 29.0, 34.0, 17.5 and 14.4, respectively for coriander; 89.8, 32.6, 7.8, 22.9, 257.8, 99.1 and 27.8, respectively for sweet fennel. As well as N3P3 x trace elements led to higher biochemical contents than the control. The increases were 0.9, 0.3 and 0.9% in essential oil; 5.4, 4.4 and 3.7% in fixed oil, 9, 7.9 and 8.2% in total carbohydrates; 2.4, 2.8 and 1.6% in soluble sugars; 5.0, 7.5 and 14.4% in crude protein; 0.8, 2.0 and 2.3% in nitrogen; 1.5, 0.6 and 0.4% in phosphorous; 1.3, 1.2 and 1.7% in potassium for anise, coriander and sweet fennel, respectively.