This monograph is devoted to different aspects associated with citric acid, inorganic citrates and their aqueous and organic solutions. It includes information about properties, occurrence and technological applications of citric acid and inorganic citrates. Phase equilibria - melting, freezing, boiling, vapour pressures, solubilities of citric acid in water, organic solvents and ternary systems are presented, correlated, and analyzed. Dynamic properties - viscosities, diffusion coefficients, electrical conductivities and surface tensions are examined. Mathematical representations of citric acid dissociation, in electrolyte solutions and in buffers are discussed. Citric acid chemistry - syntheses of citric acid, neutralization, degradation, oxidation, esterification, formation of anhydrides, amides and citrate-based siderophores is reviewed.