<p>Housing animals in an enriched environment (EE) is known to prevent the development of anxious-depressive disorders and cognitive impairments caused by various stresses. A very limited number of studies on learning and memory have used the Morris water maze and exposure of animals to proinflammatory stress (PIS) before the influence of EE. We report here the first investigations of the reverse sequence of interaction between EE and stress: animals were first kept in an EE and then exposed to PIS. For this purpose, 40 rats aged 25–45 days were placed in an EE and another 40 rats were kept in standard conditions. PIS in rats of both groups was induced by giving either singe doses of bacterial lipopolysaccharide (LPS) (350 μg/kg) (acute stress) or repeated doses of 200 μg/kg (chronic stress) 1 h before the start of behavioral tests and during these tests. Control animals were given the same volume of saline. The data obtained here indicate that rats kept in the EE found the hidden underwater platform faster and swam a shorter distance to it than rats kept in standard conditions. In animals subjected to acute and chronic LPS stress, prior housing in EE conditions led to the normalization of behavioral indicators to those seen in the control rats. In these rats, EE produced improvements in behavioral indicators on assessment of working memory. These results shows that EE has an important role in beneficial influences on the behavior of rats when seeking the safe platform.</p>