AbstractObjectiveSeparation of pups from their dam during the infancy not only has detrimental effects on the pups' brain but also affects dams' behavior. Postpartum stress may affect mothers' cognitive functions. In the present study, by using a 180‐min day−1 maternal separation (MS) paradigm, we assessed anxiety‐like behavior and locomotor activity of rat dams which experienced separation from postnatal day (PND) 1 until weaning. We tried for the first time to clarify whether such separation impairs dam's performance in the Morris water maze.MethodWe assessed dams' behavior at three time points: 24 h, 1 week, and 1 month after weaning. Therefore, the six groups consisted of control (CTRL) 24 h, 1 week, and 1 month and MS 24 h, 1 week, and 1 month, which was allocated in this study.ResultsOur results revealed that although MS‐24 h and MS‐1 week groups had intact locomotor activity, MS‐1 month group showed less locomotor activity in the open field. Moreover, MS‐induced anxiety‐like behavior was more pronounced in MS‐1 week and MS‐1 month dams. Spatial learning and memory was also impaired only in MS‐1 month dams.ConclusionWe can conclude that MS induces cognitive impairments in dam that may appear not immediately after the separation but a few weeks after such stressful event.