Our studies on the seleno-organic compounds were focused at their activities as the modest cytokine inducers in human peripheral blood leukocyte cultures. Our bioassays used in the screening methods were based on the quantitative determinations of mainly two types of cytokines: interferons (IFNs) and tumor necrosis factors (TNFs). More recently we have found that several of the compounds have direct immunotropic actions in vitro and in vivo, in mice and in chickens. The paper summarizes the data related to the cytokine-inducing activity of 65 seleno-organic compounds divided into 4 groups according to their chemical structures. The reference compound was ebselen, the well known experimental drug with various biological activities. Approximately 50% of the compounds were found to be active in our bioassays. The selected compounds induced also IL-6 and GM-CSF. Their activities were clearly correlated with defined chemical structures as well as with the presence of selenium. We suggest that some of the selected by us compounds, other than ebselen, are interesting as immunostimulants and potential antiviral agents and cytokine inducers active in humans.