Caspases are key effectors of the apoptotic process. Some of them play an important role in the immune system, being involved in proteolytic maturation of the key cytokines including interleukin-1beta (IL-1beta) and interleukin-18 (IL-18). The latter directs the production of interferon gamma (IFN-gamma). Among pathogens, particularly viruses express various modulators of caspases that inhibit their activity by direct binding. By evading the apoptotic process viruses can better control their production in the infected cell, and avoid the attack of immune system. Targeting of the maturation of the key cytokines involved in the initiation of (antiviral) immune response helps to avoid the recognition and eradication by the immune system. The three main classes of caspase inhibitors frequently found among viruses include serpins (CrmA/SPI-2), viral IAPs (vIAPs) and p35. Their molecular mechanism of action, structure and the overall influence on cellular physiology is discussed in the review below.