Single-stem and branched epsilon-FeSi nanowires with diameters ranging from 5 to 100 nm (see figure) are synthesized using a chemical vapor deposition method. These nanowires, including branches, are single crystalline and exhibit a cubic structure with [111] growth direction. Electrical and magnetic measurements show that these nanowires exhibit properties consistent with those of the bulk material, with branch-induced charge-carrier introduction playing an important role.