Little is known about the characteristics, social circumstances and mental health of women who give a child up for adoption. This paper reports data from a longitudinal study of 8556 women interviewed initially at their first obstetrical visit. In total, 7668 proceeded to give birth to a live singleton baby, of which 64 then relinquished the baby for adoption. Relinquishing mothers were predominantly 18 years of age or younger, in the lowest family income group, single, having an unplanned and/or unwanted baby and reported that they were not living with a partner. These women were somewhat more likely to manifest symptoms of anxiety and depression both prior, and subsequent to, the adoption, but the majority of relinquishing mothers were of 'normal' mental health. The decision to relinquish a baby appears to be a consequence of an unwanted pregnancy experienced by an economically deprived single mother rather than the result of emotional or psychological/psychiatric considerations. These findings document a particular dimension of the impact of poverty on health.