<p>Abiotic stress limits agricultural sustainability, so the focus is on improved productivity and stress resilience using eco-friendly alternatives. Hydrogen sulfide (H₂S) is an important signaling molecule regulating plant stress responses. In this context, the present study revealed the potential of sodium hydrosulfide (NaHS), an H₂S donor, in salt stress regulation of <i>Luffa aegyptiaca</i> (sponge gourd) via hydroponics. NaHS rescued the morphological and biochemical traits of salt-stressed plants and enhanced their antioxidant potential by increasing H₂S levels. The reduced oxidative stress enhanced photosynthetic pigments by 33–39%, due to the inhibition of salt-led chlorophyll degradation, which further enhanced carbohydrate and protein levels. Moreover, the activity of Nitrate Reductase (NR) and Nitrite Reductase (NiR) was significantly reduced on NaCl exposure, which likely decreased nitrite absorption. The inhibition of ammonium assimilation due to reduced Glutamate Synthase (GOGAT) activity further enhanced stress and significantly reduced the morphological parameters of salt-stressed sponge gourd. However, H₂S supplementation via NaHS enhanced the nitrate uptake due to the increased activity of nitrogen metabolizing enzymes, including NiR, NR, and GOGAT, thus promoting plant growth. Additionally, the treatment of sponge gourd with scavenger hypotaurine (HT) and inhibitor propargylglycine (PAG) reversed the NaHS-mediated morphological and biochemical changes, thus validating the potential role of NaHS in maintaining sponge gourd growth during salt stress. Hence, NaHS has induced salt stress tolerance by positively impacting the antioxidant system and nitrogen metabolism in sponge gourd. The present study thus indicates that NaHS/ H₂S exposure can be a cost-effective alternative to conventional chemical fertilizers, targeting agricultural sustainability.</p>