Studies 1 and 2 investigated how maternal severe mental illness (SMI) related to mothers’ mind–mindedness (appropriate and nonattuned mind-related comments). Study 1 showed that mothers with SMI (n = 50) scored lower than psychologically well mothers for both appropriate and nonattuned comments, whereas mothers with SMI in Study 2 (n = 22) had elevated levels of nonattuned comments. Study 2 also tested the efficacy of a single-session video-feedback intervention to facilitate mind–mindedness in mothers with SMI. The intervention was associated with a decrease in nonattuned comments, such that on discharge, mothers did not differ from psychologically well controls. Study 3 assessed infant–mother attachment security in a small subset of intervention-group mothers from Study 2 (n = 9) and a separate group of standard care mothers (n = 30) at infant mean age 17.1 months (SD = 2.1). Infants whose mothers completed the intervention were more likely to be securely attached and less likely to be classified as insecure–disorganized than those of mothers who received standard care. We conclude that a single session of video-feedback to facilitate mind–mindedness in mothers with SMI may have benefits for mother–infant interaction into the second year of life.