Cerebral inflammation as well as systemic immunological alterations have been reported in Alzheimer’s disease (AD). We examined the production of the proinflammatory cytokines interleukin-6, interleukin-12, interferon-γ, and tumor necrosis factor-α in whole blood cell cultures of AD patients and age-matched controls. The production of all measured cytokines after mitogen stimulation is significantly decreased in the AD group compared to controls. The results reflect an attenuated secretory activity of monocytes/macrophages, but also of T-helper cells. The data sustain the assumption that a systemic, possibly age-related alteration of immune mechanisms may play a pathogenetic role in the development of AD.