We have compared the local structure of electrochemically lithiated SnO with Sn/Li alloys using 7Li to study the environment of the Li ion and extended X-ray absorption fine structure to study the environment of the Sn ion. Although a widely accepted simple model suggested that the electrochemically lithiated SnO should be similar to Sn/Li alloys of corresponding composition, we find this is true only at low Li concentrations. The addition of more Li to the structure produces, for both the Li and the Sn, features which are difficult to reconcile with the simple model, and suggest the presence of direct Sn–O interactions.