Carboxylic acids are industrially important and specifically used for the manufacturing of soaps and detergents and for various other chemical processes. As a result, wastewater derived from such industries generally contains significant amounts of these acids, posing threats to aquatic life, and thus needing detoxification by suitable treatment methods. In the present work, the degradation of different aliphatic carboxylic acids by bare and Ag-loaded TiO2 under UV light irradiation was investigated. The acids were photo-decomposed to CO2 with a linear decrease in the respective concentrations as a function of chain length/carbon atoms (C-1-C-8) and irradiation time. Small carboxylic acids, i.e., formic, acetic and propionic acid, exhibited faster rates of degradation than longer ones, i.e., butanoic, valeric and ethyl hexanoic acid; Ag loading did not significantly improve the TiO2 photocatalytic activity.