This document summarizes key aspects of drug excretion from the body. It discusses excretion through the kidneys including glomerular filtration and tubular secretion. It also covers biliary excretion through the liver and factors that influence the various orders of excretion such as zero-order and first-order kinetics. The concepts of half-life, clearance, volume of distribution, bioavailability and achieving steady-state concentrations with repetitive dosing are defined. Considerations for dosing adjustments in renal disease are provided.