Current study on “ICM in onion with special emphasis on Nano fertilizers” was investigated at Main Agricultural Research Station, UAS, Dharwad during kharif season of 2022 and 2023 in a randomized block design with thirteen treatments and replicated thrice.Results revealed that, each treatment had a considerable effect on the observed growth, yield, quality, post-harvest factors, pest and disease reaction and soil quality characteristics in both the seasons 2022 and 2023. Among all treatments, pooled data of two years revealed that treatment T11 (RPP (50 % recommended dose of N P and foliar spray of Nano urea & Nano DAP @ 4 ml l-1, twice at 45 and 60 DAS + 100% recommended K) + bentonite-S (Sulphur @ 50 kg ha-1) + boron @ 2. 5 kg ha-1 + Nano-Zn & Nano-Fe each at 2 ml l-1, applied twice at 45 and 60 DAS). had registered significantly higher plant height (62.29 cm ), neck diameter (13.14 mm) chlorophyll content (64.76 spad unit) at 90 DAS and also recorded significantly higher total bulb yield (23.11 t ha-1), TSS (13.61 °Brix), Pyruvic acid (3.00 μmoles ml-1), sugar Reducing: 2.97, Non-reducing: 3.95 and Total sugar : 5.94 mg g-1), similarly higher total uptake (Nitrogen: 620.20, Phosphorous 97.01 and Potassium: 407.22 kg ha-1), B:C ratio (2.99). Furthermore, lowest sprouting per cent (7.77) and higher per cent of marketable bulb (58.10%) was also noticed with above treatment. It was statistically on par with treatment T12 (RPP (50 % recommended dose of N P and foliar spray of Nano urea and Nano DAP @ 4 ml l-1, twice at 45 and 60 DAS + 100% recommended K)) + bentonite-S (Sulphur @ 50 kg ha-1) +Vegetable Special @ 5g l-1 twice at 45 & 60 DAS) and T6 (RPP + bentonite-S (Sulphur @ 50 kg ha-1) + Vegetable Special @ 5 g l-1 applied twice at 45 and 60 DAS). However, RPP (T1) recorded significantly lower plant height (49.76 cm), neck diameter (8.79 mm) chlorophyll content (56.68 spad unit) at 90 DAS and also recorded significantly lower bulb yield (16.93 t ha-1), TSS (10.91 °Brix), Pyruvic acid (1.29 μmoles ml-1), sugar (reducing:1.58, non-reducing:2.29 and total:4.18 mg g-1). Correspondingly lower total uptake of nitrogen, phosphorous and potassium (388.84, 56.15 and 258.96 kg ha-1 respectively), B:C ratio (2.28) and higher sprouting per cent (8.75) and lower per cent of marketable bulb (48.90) compared with above treatment were noted with T1.