Electroless Ni-B coatings find versatile use due to high hardness and wear resistance that gets enhanced due to incorporation of hard nanoparticles. However, incorporation of nanoparticles suffers from high degree of agglomeration owing to small size and high surface energy. The present investigation aims at the deposition of electroless Ni-B-nano Al2O3 coatings using Sodium Dodecyl Sulphate (SDS) as surfactant and attempts to find the optimum amount of nano-alumina powder for superior tribo-mechanical characteristics. Thus, electroless Ni-B-nano Al2O3 coatings were prepared with varying concentrations of nano-Al2O3 (0 g/l, 2.5 g/l, 5 g/l, 7.5 g/l, 10 g/l, 12.5 g/l) in a chemical bath. To minimize agglomeration of alumina nanoparticles, ultrasonication technique was used. Coatings were characterized by Scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Raman spectroscopy. Hardness, elastic modulus, wear resistance and corrosion resistance of the coatings were evaluated. Wear resistance and corrosion properties of the coatings show an improvement with the increase in the concentration of nanoparticles (Al2O3) in the bath up to 10 g/l but on further increasing the concentration to 12.5 g/l deterioration in wear resistance and corrosion resistance is observed. As compared to binary Ni-B coating, the coating prepared with 10 g/l concentration of nanoparticles shows an increase of around 30% and 60% for Vicker’s microhardness and elastic modulus, respectively. The optimum amount of alumina nano-powder in the coating bath is thus found as 10 g/l considering superior elastic modulus, corrosion resistance and wear resistance.