Conditions governing the formation of electrolytic hexagonal nickel in baths containing , , and were investigated. A mixed structure of face‐centered‐cubic and hexagonal‐close‐packed forms was always present in deposits made from baths containing a relatively large amount at higher current densities (>0.2 amp/dm2) and lower bath temperatures (<40°C). Deposits with a mixed structure are found to contain more occluded hydrogen than deposits with a simple face‐centered‐cubic structure. The possible connection between higher hydrogen content and the presence of the mixed structure under certain bath conditions is discussed.