Magnesium is one of the lightest structural metals used in different industrial sectors and many works in the literature have studied its reinforcement by filler addition. Basalt fibers are natural fillers that have good mechanical properties, excellent resistance to high temperatures, and lower cost than carbon fibers. Considering this, in recent years, they have been increasingly used in the production of composite materials with polymeric matrices. However, very little information is available in the literature about the use of basalt fibers as reinforcement in metal matrix composite materials. It is well known that the impregnation of fiber reinforcement affects the mechanical behavior of the composite materials. The aim of this study was to investigate the impregnation and the behavior of basalt fibers in a magnesium alloy composite material manufactured by a centrifugal casting technique.