There is immense need of enhancing the content and yield of active constituents of medicinally importantplants in view of their massive demand worldwide. Various phytohormones have proved effective inthis regard. Gamma-rays irradiated sodium alginate (ISA), triacontanol (TRIA) and 28-homobrassinolide(HBR) have also proven as potent plant growth promoting substances for a number of agricultural andhorticultural crops. Considering the medicinal importance, a pot experiment was conducted to explorethe individual as well as combined effect of best foliar doses of ISA, TRIA and HBR on growth, yieldand quality of mint (Mentha arvensis L.). The spray of ISA, TRIA and HBR, applied alone on plants, waspositively effective. However, the effect of their combined application was much pronounced as comparedto that of their individual application; it improved most of the plant growth attributes, physiologicaland biochemical parameters, herbage yield and the content and yield of active constituents of mintsignificantly studied at 100 and 120 DAP. Of the seven spray-treatments [(i) Control, (ii) 100 ppm ISA,(iii) 10⁻⁶M TRIA, (iv) 10⁻⁷M HBR, (v) 100 ppm ISA + 10⁻⁶M TRIA, (vi) 100 ppm ISA + 10⁻⁷M HBR, (vii)100 ppm ISA + 10⁻⁶M TRIA + 10⁻⁷M HBR], 100 ppm ISA + 10⁻⁶M TRIA + 10⁻⁷M HBR proved to be the best.The combined application resulted in the highest content and yield of essential oil (EO) over the controlby 42.1 and 43.9% and 114.0 and 121.7% at 100 and 120 DAP, respectively. This combined treatment ofplant growth regulators (PGRs) also proved the best, increasing the content of menthol, l-menthone,isomenthone and menthyl acetate by 7.5 and 6.2%, 31.8 and 32.1%, 25.8 and 21.7%, and 40.1 and 37.2%,respectively, over the respective control at 100 and 120 DAP. As compared to the control, it increased theper plant yields of menthol, l-menthone, isomenthone and menthyl acetate by 129.9 and 135.5%, 190.0and 194.4%, 162.5 and 164.3%, and by 225.0 and 187.5% at 100 and 120 DAP, respectively.