Microgreens have gained attention as promising functional foods due to their high concentrations of essential nutrients and bioactive compounds, which can contribute to diet diversification and the prevention of malnutrition. Among them, green pea (Pisum sativum L.) microgreens stand out for their nutritional value and appealing organoleptic properties. However, a comprehensive characterization of their nutritional composition and bioactive properties is still limited. This study aimed to cultivate green pea microgreens and evaluate their nutritional profile and antioxidant activity. The microgreens were grown under greenhouse conditions using Siro Bio substrate (NPK 9:2:2, 2 kg/m³), with irrigation via nebulization. They were harvested 25 days after sowing, and the emergence rate was monitored daily. Post-harvest, biomass yield and moisture content were determined. Chlorophyll content was analyzed via spectrophotometry, mineral composition was analyzed using atomic absorption spectrometry, and soluble sugars and organic acids were analzyed by means of high-performance liquid chromatography. A hydroethanolic extract was prepared to quantify total phenolics (Folin–Ciocalteu method) and evaluate antioxidant activity through DPPH free radical scavenging and TBARS formation inhibition assays [3]. The microgreens showed an emergence rate of approximately 80% and a predominance of chlorophyll a over chlorophyll b. Glucose was the sole detected soluble sugar (2.18 g/100 g dw). Among organic acids, oxalic (13.75 g/100 g dw), citric (0.51 g/100 g dw), and fumaric (0.02 g/100 g dw) acids were quantified, while ascorbic acid was found only in trace amounts. Mineral analysis revealed high levels of potassium (5.67 g/100 g dw), calcium (3.14 g/100 g dw), iron (10.17 mg/100 g dw), and zinc (6.38 mg/100 g dw), highlighting the microgreens’ potential as a mineral-dense food. The hydroethanolic extract showed a total phenolic content of 133 mg GAE/g but demonstrated moderate antioxidant activity compared to the positive control, Trolox. This study expands the current knowledge on the nutritional value and antioxidant properties of green pea microgreens, reinforcing their suitability for inclusion in balanced and sustainable diets.