The objective of this work is to demonstrate how treasury management is related to the liquidity of the Empresa Prestadora de Servicios de Saneamiento. The data collection was carried out through accounting documentary analysis and a survey to the accounting department and treasury area personnel. The Sanitation Services Provider Company has management directives and documents. However, these directives are outdated, do not perform the records, management, analysis of income and expenses as established in the regulations, which leads to workers do not develop effectively with the treasury functions and thus the failure to pay the commitments on the agreed dates. The treasury management is directly related to the liquidity in the Empresa Prestadora de Servicios de Saneamiento, observing that the entity has outdated manuals and internal directives, a weak collection management and payment management, inadequate treasury budget and regular technological tools that affect liquidity.