<p>An experiment was conducted to study the effect of pre-harvest application of spermine on fruit ripening, yield and quality of litchi cv. Deshi. Spermine was applied at 0.10, 0.20 and 0.30 mM concentration on the litchi plants at 20, 40 and 20 + 40 days after fruit setting. It was observed that the fruit ripening delayed by 9 days as compared to control when 0.10 mM spermine solution was applied at 40 days after fruit set. Maximum fruit weight (22.74&#xa0;g) and yield per plant (24.24&#xa0;kg) was recorded under pre-harvest application of 0.10 mM spermine at 40 days after fruit set. The membrane electrolytic leakage, peroxidase and polyphenol oxidase activities in the fruit pericarp were recorded minimum in this treatment with statistically at par result in its two applications (0.10 mM) at 20 and 40 days after fruit set. However, the activities of catalase and phenylalanine ammonia-lyase were recorded maximum in these two treatments. Further, the biochemical attributes of the harvested fruit in terms of TSS, total sugar content, ascorbic acid and anthocyanin content, total phenol and flavonoid content as well as antioxidant capacity were also enhanced significantly by the application of 0.10 mM spermine at 20 and 40 days after fruit set (23.06 °B, 17.34%, 43.78&#xa0;mg 100&#xa0;g^-1 FW, 33.98&#xa0;mg 100&#xa0;g^-1 FW, 596.11&#xa0;µg GAE g^-1 FW, 33.85&#xa0;µg CE g^-1 FW and 6.41 µ mol TE 100&#xa0;g^-1 FW, respectively) with par value in its single application at 0.10 mM concentration at 40 days after fruit set (22.77 °B, 17.23%, 43.56&#xa0;mg 100&#xa0;g^-1 FW, 33.58&#xa0;mg 100&#xa0;g^-1 FW, 594.11&#xa0;µg GAE g^-1 FW, 33.58&#xa0;µg CE g^-1 FW and 6.38 µ mol TE 100&#xa0;g^-1 FW, respectively). Hence, it can be concluded that pre-harvest application of 0.10 mM spermine at 40 days after fruit set is optimum for improving the yield and quality of litchi cv. Deshi with delayed harvesting which can makes the best quality litchi fruits available in the market for longer period of time.</p>