In this study, the intracellular signal transduction pathways leading to the production of TNF-α and superoxide anions by amyloid-β-stimulated primary human monocyte-derived macrophages was investigated. Using Western blotting and specific inhibitors it is shown that both ERK 1/2 and p38 MAPK signal transduction pathways as well as PKC are involved in the amyloid-β-stimulated superoxide anion production. In contrast, only ERK 1/2 MAPK seems to be involved in TNF-α production: questioning the connection between PKC and ERK 1/2 activation. Our results suggest the use of ERK 1/2 MAPK inhibitors in the prevention of macrophage activation in the context of Alzheimer's disease.