The objective of the study was to examine mental health referrals outcomes among obstetric patients at risk for depression.Fifty-one perinatal women who were offered mental health referrals were queried about their behaviors at 4 steps in the treatment engagement process and factors facilitating or impeding each step.Although 59% of at-risk women accepted mental health referrals, only 27% ultimately engaged in treatment. Women who proactively sought help via a hotline were more likely to accept referrals (P < .001), contact a referred provider (P < .001), and engage in treatment (P < .05) than those who received unsolicited referrals after screening at-risk for depression. Barriers to successful treatment linkage were identified at the patient, provider, and system levels.Only a minority of women who are at risk for perinatal depression and receive mental health referrals ultimately engage in treatment. Successful linkage may be enhanced via interventions targeting identified barriers; such interventions require prospective evaluation.