In the present study, a phytochemical screening, antioxidant and antimicrobial activity in vitro were studied for the methanolic extract of the leaves of the plant Urtica dioica L. The DPPH method was used to evaluate the antioxidant activity, and the agar disk diffusion method determined the antibacterial power. The results of the qualitative phytochemical analysis show a high content of phenolic compounds characterized by a higher presence of saponins, and a medium richness in tannins with a low content of flavonoids, free quinines and sterols. On the other hand, the absence of alkaloids is observed. For the results of antioxidant activity, the percentage of inhibition of DPPH is 82.76%, 77.85%, and 74.83% for the concentrations 25mg/ml, 12.5mg/ml, and 6.25mg/ml respectively. The lowest percentage of inhibition is noticed for the concentration of 3,15mg/ml with 29, 84%. Our plant shows positive antioxidant activity with an IC50 of 4.69mg/ml. In addition, the antimicrobial activity revealed the most significant effect for Pseudomonas aeruginosa strain with an inhibition zone of 9mm to 10mm, with concentrations of 400mg/ml, 300 mg/ml and 200 mg/ml, respectively. Our results suggest that the methanolic extract of Urtica dioica L, as a pleasant natural antioxidant and antimicrobial agent, can be applied in the preservation of food products while conducting further studies on the bioactive molecules of this plant to determine their mechanism of action.