Signal transduction through the interleukin-1 receptor (IL-1R) pathway mediates a strong pro-inflammatory response, which contributes to a number of human diseases such as rheumatoid arthritis. Within the IL-1 family, IL-1alpha and IL-1beta are both agonistic ligands for IL-1R, whereas IL-1 receptor antagonist (IL-1ra) is an endogenous antagonist that binds to IL-R, but does not signal. Therefore, the ideal therapeutic strategy would be blocking both IL-1alpha and IL-1beta, but not IL-1ra. However, due to low sequence homology between the three members of the family, it has been exceedingly difficult to identify potent therapeutic agents, e.g., monoclonal antibodies (mAbs), that selectively recognize both IL-1alpha and IL-1beta, but not IL-1ra. Currently, several anti-IL-1 therapeutic agents in clinical development either inhibit only IL-1beta (i.e., anti-IL-1beta mAb), or recognize all three ligands (i.e., anti-IL-1R mAb or IL-1R Trap). We have recently developed a novel dual variable domain immunoglobulin (or DVD-Ig) technology that enables engineering the distinct specificities of two mAbs into a single functional, dual-specific, tetravalent IgG-like molecule. Based on this approach, we have developed anti-human IL-1alpha/beta DVD-Ig molecules using several pairs of monoclonal antibodies with therapeutic potential, and present a case study for optimal design of a DVD-Ig agent for a specific target pair combination.