Nonischemic dilated cardiomyopathy (DCM) is an uncommon cause of heart failure but has widespread importance because it is the cause of 45% of heart transplantations. Multiple experimental and clinical lines of evidence have implicated altered immunity in the pathogenesis of DCM. However, advances in the understanding of the mechanisms of altered immunity have not affected the diagnosis or treatment of DCM. In recognition of this problem, the National Institutes of Health sponsored an expert workshop with 2 aims: to review the current understanding of inflammation and immunity as they relate to DCM and to identify the most promising areas for future clinical research efforts in the field. This report summarizes the scientific opportunities, perceived needs and barriers, and workshop recommendations on research directions in DCM. The major recommendations from the members of the workshop are organized according to the following themes: cardiotropic viruses, innate and acquired immune responses, environmental factors, novel diagnostics, and novel therapeutics.