This paper study the influence of water content on the mechanical behavior and failure process of an unsaturated argillaceous rock. For this, uniaxial compression tests with acoustic emission recording were conducted on specimens at different levels of relative humidity. Results indicate that uniaxial compressive strength and the elastic modulus increases with a reduction in the water content. Additionally, rock moisture seems to influence the volumetric deformation. Analyzing the volumetric stress-strain curves in conjunction with acoustic emission technique was possible to identify the crack initiation and damage stress thresholds at different values of relative humidity.