Cytokines play an important role in the progression of autoimmune diseases, and therefore it is not surprising that their levels may be altered in some of these diseases. Interleukin-3 (IL-3), which is an hematopoietic growth factor as well as an important factor that aids in embryo implantation and placental development, was found to be decreased both in pregnant women with antiphospholipid syndrome (APS) compared with a control group, and in animal models of APS. Treatment of animals having APS with IL-3 succeeded in prevention of disease manifestations. In this communication we review IL-3 and APS interrelationship, and discuss the role of aspirin and other commonly used drugs, with respect to IL-3 levels in APS.