Contrast-enhanced digital breast tomosynthesis (CE-DBT) is a novel modality for imaging breast lesion morphology and vascularity. The purpose of this study is to assess the feasibility of dual-energy subtraction as a technique for CE-DBT (a temporal subtraction CE-DBT technique has been described previously). As CE-DBT evolves, exploration of alternative image acquisition techniques will contribute to its optimisation. Evaluation of dual-energy CE-DBT was conducted with Institutional Review Board (IRB) approval from our institution and in compliance with federal Health Insurance Portability and Accountability Act (HIPAA) guidelines. A 55-year old patient with a known malignancy in the right breast underwent imaging with MRI and CE-DBT. CE-DBT was performed in the medial lateral oblique view with a DBT system, which was modified under IRB approval to allow high-energy image acquisition with a 0.25 mm Cu filter. Image acquisition occurred via both temporal and dual-energy subtraction CE-DBT. Between the pre- and post-contrast DBT image sets, a single bolus of iodinated contrast agent (1.0 ml kg(-1)) was administered, followed by a 60 ml saline flush. The contrast agent and saline were administrated manually at a rate of approximately 2 ml s(-1). Images were reconstructed using filtered-back projection and transmitted to a clinical PACS workstation. Dual-energy CE-DBT was shown to be clinically feasible. In our index case, the dual-energy technique was able to provide morphology and kinetic information about the known malignancy. This information was qualitatively concordant with that of CE-MRI. Compared with the temporal subtraction CE-DBT technique, dual-energy CE-DBT appears less susceptible to motion artefacts.