The usages of natural fibers as reinforcement material in composites have shown acceptable results. The composite with uniformly distributed fibers under desired orientation is in the usual practice of casting. The studies of natural fiber reinforced composites have shown their utility in real practice. Past researchers have investigated various types of Basalt reinforced materials in the form of fiber, fabric, rods, etc. In this present work, a study on the mechanical properties of uniformly distributed randomly oriented basalt rock fiber (BRF) reinforced composites is presented. The basalt fiber of 13 mm ± 1 mm length having 1 mm width and polymer matrix are used for casting the composite specimen. An unsaturated polyester resin is used as matrix material along with Methyl Ethyl Ketone Peroxide (MEKP) and Cobalt Naphthenate as catalyst and hardener respectively. A ratio of 1:1:50 of Methyl Ethyl Ketone Peroxide, Cobalt Naphthenate, and Unsaturated resin are adopted to prepare the matrix solution for the fabrication process. The composites specimens of 15, 20, 25, 30, 40 and 45% fiber volume fraction are fabricated. The results of the present study have shown the higher value of tensile and flexure strength at 40% fiber volume fraction. Hence the 40% fiber volume fraction is the optimum percentage for uniformly distributed, randomly oriented BRF reinforced composites. © Society for Experimental Mechanics, Inc. 2020.