Background and Objectives: Parsley herb has various biological properties and used in food and pharmaceutical industries. Biostimulants represent one area of research that has the potential to increase medicinal and aromatic plants (MAP) productivity. The aim of this study was to evaluate the growth and chemical composition of parsley plant under some biostimulants treatments. Materials and Methods: Parsley plants were subjected to different concentrations of L-tryptophan (LTRYP, 100 and 200 mg L1), trans-cinnamic acid (TCA, 10 and 20 mg L1) and distilled water as control. Plant growth characters (PGC), plant height (cm), herb fresh weight (FW) and herb dry weight (DW)}, essential oil (EO), photosynthetic pigments (PSP), total carbohydrates (TCAR), total soluble sugars (TSS) and antioxidant enzymes [superoxide dismutase (SOD), catalase activity (CAT), peroxidase (POX)] were evaluated though various growth stages. The averages of data were statistically analyzed using two-way analysis of variance (ANOVA-2). Results: Obtained results reported that the treatment 200 mg L1 of LTRYP produced the highest values of PGC, EO yield and main components of EO (apiol, myristicin, α-pinene, β-pinene), PSP, TCAR, TSS, SOD, CAT and POX. Conclusion: Generally, the highest values of growth, yield and chemical composition of parsley plants were obtained with 200 mg L1 (LTRYP) treatment.