Protein kinase C (PKC) is a family of serine/threonine protein kinases that controls downstream functions of other proteins and plays an important role in several signal transduction cascades; it is made up of a regulatory domain and catalytic domain tethered by a hinge region. PKC inhibitors are of interest as therapeutics for a wide range of diseases including cancer, complications from diabetes, heart failure, bipolar disorder, and pain. While pharmaceutical companies continue to search for novel specific PKC inhibitors, a number of small molecule inhibitors are currently available. Some of these act specifically while others inhibit a wider range of kinase activity.