Pregnancy has an important impact on the maternal immune system, associated with a shift in the Th1/Th2 cytokine balance towards a type‐2 response. However, listeria induced Th1 type cytokines are essential in host protection against this facultative intracellular bacterium. We have analyzed and compared the kinetics of maternal serum concentrations of IFN‐γ, IL‐10, TNF‐α, IL‐6 and KC by ELISA. Serum IFN‐γ levels in infected pregnant mice were significantly reduced in comparison to infected virgin animals, while IL‐10 levels were increased, being significantly higher on days 3 and 6 p.i. as compared to infected virgin mice. Upon L. monocytogenes infection, circulating TNF‐α concentrations were below the detection limit. However, on day 6 p.i., in pregnant mice elevated levels of TNF‐α were noticed, correlating to the severity of disease. Increased concentrations of IL‐6 have been shown to follow the kinetics of bacterial numbers in the liver of infected animals. Murine chemokine KC production in maternal circulation followed a similar pattern as IL‐6.In comparison to virgin animals, pregnant mice mount lower levels of protective Th1 cytokines and are unable to eliminate the pathogen. Increased serum concentrations of IL‐10, along with proinflammatory cytokines, may well contribute to the severity of pregnancy‐associated listeriosis.Maternal serum IL‐6 level showed the highest correlation with the course of infection and pregnancy outcome.