There is an increasing awareness of the role of inflammation in cancer. Immune responses can limit the growth of some tumors, but paradoxically, may promote the growth of others. Cytokines are critical mediators of both the innate and the adaptive immune responses. In this chapter, we will describe several methods for the detection of inflammatory cytokines. First, we will describe a protocol for quantification of cytokine mRNA by real-time quantitative PCR. In addition, we will describe detection of cytokine proteins by ELISA as well as by novel cytokine bead arrays. Finally, a method will be described for in situ detection of cytokine production by immunohistochemistry.