The dislocation microstructure found in the binary ferritic alloy, Fe-10% Cr, has been characterized for damage levels ranging from 0.3 to 100 dpa. The specimens were irradiated at 850 K with a “triple beam” of He⁺, D⁺, and 4 MeV Fe⁺⁺ ions. Transmission electron microscopy revealed that dislocation loops were dominant in the dislocation microstructure from 0.3 to 3 dpa. At 0.3 dpa the loops were round to slightly rectilinear in shape, whereas at higher doses the majority of the loops had a convoluted shape that indicated preferential growth in the ⟨110⟩ directions. Analyses showed that all of the loops at low doses and the convoluted loops at 3 dpa were near-edge interstitial loops with b = a⟨100⟩. At 3 dpa, round interstitial loops with b = a/2⟨111⟩ were also observed. Network segments with b = a/2⟨111⟩ were found at the intersection of a⟨100⟩ loops with a/2⟨111⟩ loops. At damage levels greater than 10 dpa, the structure consisted of a coarse distribution of network segments along with a few loops with b = a/2⟨111⟩. At 30 and 100 dpa a relatively low dislocation density, <10¹⁴ m⁻², was found. The effects of segregation on the observed dislocations and the implications of the observations on the current understanding of dislocation evolution and damage mechanisms in ferritic materials are discussed.