Alstroemeria (Alstroemeria hybrida) is considered one of the top ten commercially important and popular cut flowers worldwide and has been among the most successful cut flowers in recent decades. However, quality deterioration from harvest to marketing and export remains one of its major challenges. This study investigated the effects of silver nanoparticles synthesized from Moringa oleifera leaf extract at concentrations of 10, 15, and 20 mL L⁻¹, in combination with 3% sucrose, and distilled water as the control, on postharvest characteristics of cut Alstroemeria flowers cv. Red Sensation. The experiment was conducted as a factorial arrangement in a completely randomized design with three replications in 2024. Measured traits included fresh flower weight, flower diameter, electrolyte leakage, water uptake, total soluble solids, total sugars, total chlorophyll, anthocyanin content, and the activity of antioxidant enzymes including ascorbate peroxidase (APX) and catalase (CAT). The results indicated that the application of silver nanoparticles synthesized from moringa leaf extract significantly improved several morphological and physiological characteristics of cut Alstroemeria flowers. Among the treatments, the concentration of 15 mL L⁻¹ showed the best overall performance in terms of quantitative and qualitative traits. Therefore, the use of silver nanoparticles synthesized from moringa extract can be proposed as an effective and environmentally friendly approach to enhance the postharvest quality of Alstroemeria cut flowers