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.