This study deals with the selection of optimum parameters for friction stir processing of Al alloy 6061-T6 reinforced with a hybrid nanoparticle (B4C and SiO2) in terms of their effect on the mechanical properties (hardness, tensile strength, and wear resistance) using Taguchi method. This work was carried out under four parameters each one running in three levels; rotational speeds (<i>800</i>, <i>1000</i> and <i>1200</i>) rpm, travel speeds (<i>10</i>, <i>20</i>, and <i>30</i>) mm/min, holes depth (<i>2</i>, <i>2.5</i>, and <i>3</i>) <i>mm</i>, and mixing ratio of (SiO2/B4C) nanoparticles (<i>1/1</i>, <i>1/2</i>, and <i>1/3</i>), using <i>L9</i> (<i>34</i>) Taguchi orthogonal array. Tensile strength and microhardness tests were conducted to evaluate the mechanical properties, in addition to the wear resistance test which is carried out using a pin-on-disk device. The microstructure was examined by optical microscopy, field emission scanning electron microscopy, and x-ray diffraction analysis. It was found that the highest tensile strength (<i>223</i>) <i>MPa</i> at <i>1200 rpm</i> rotational speed, <i>30 mm/min</i> traverse speed, <i>2.5 mm</i> holes depth, and <i>1/2</i> (SiO2/B4C) nanoparticles mixing ratio, the highest hardness reached is (<i>155</i>) HV, then decreases in the direction of thermomechanically affected zone (TMAZ), heat affected zone (HAZ), and the base material at (<i>1200</i>) <i>rpm</i> rotational speed, (<i>30</i>) mm/min linear speed, a hole depth of (<i>2</i>) mm and (<i>1/3</i>) mixing ratio of (B4C/SiO2) nanoparticles. The wear behavior was of a mild type or an oxidative type at low loads (<i>5 N</i>), which became severe or metallic wear at higher loads (<i>20 N</i>) at fixed sliding time and speed. The (ANOVA) table has been used to determine which parameter is the most significant using MINITAB software.