Uranium in its natural state is composed of three distinct isotopes: 238, 235, and 234U. This heavy metal has a substantial level of chemical toxicity for biota. It transports radioactivity from the earth into the indoor environment, raising the risk of lung cancer. Its uptake by plants can result in cellular damage and disruption of cellular homeostasis and its regulation. The pH of the environment and the presence of complex ligands are two factors that affect the chemical speciation of uranium in the environment. This chemical speciation determines the destiny, transportation, bioavailability, and dangerous potential of uranium. Both bioavailability and toxicity are extremely sensitive to how an individual is exposed to them. In this chapter, we will focus on and review various sources of uranium as well as its speciation, absorption, toxic effects, and biological remediation techniques in soil-plant systems.