The dipteran species Chironomus xanthus is being used as a model species in ecotoxicology studies. The aim of this study was to evaluate the bioindicator species C. xanthus in laboratory tests for its sensitivity to different concentrations of sodium chloride (NaCl). The life cycle of the C. xanthus species was assessed, and ecotoxicological tests were carried out using acute and chronic trials. The tests were conducted using concentrations of 0.5, 1, 2, 4, 8, 16 and 32 g.L-1 for the acute test, plus control (ASTM medium), with exposures of 24 and 48 hours. For the chronic test, the concentrations were 0.0625; 0.125; 0.25; 0.5 and 1 g.L-1, plus control (ASTM medium), with exposure of 28 days. The study of the sensitivity of C. xanthus to NaCl provides support for assessing whether the environment, especially aquatic ecosystems, can be contaminated by this substance.