Partners are often enlisted in the care and management of pregnant women with severe mental illness (SMI); however their needs and capacity to provide support is not yet well understood. We aim to describe the psychosocial characteristics, health behaviours and appraisals of parenthood of men accompanying their partners with SMI to a specialist antenatal clinic. Methods: A 36-question, study-specific cross sectional survey was completed by men whose partners with SMI were receiving antenatal care at a specialist multidisciplinary clinic over a 12-month period. Results: A high percentage of eligible participants (40/41, 97.5 ) completed the survey. Overall 25 depended for income on social security benefits; 60 reported smoking, alcohol and drug using behaviours that carried high health risks; 18 had a history of domestic violence order (DVO) being taken out against them, and 12.5 a documented history of bipolar or schizophrenic illnesses. Despite these risk factors they reported high satisfaction with their intimate partner relationships, and all anticipated the birth of the baby and impending fatherhood with enthusiasm, optimism and perhaps idealisation. Conclusions: Men who are the pregnancy partners of women with SMI, appear to be an especially vulnerable population, who report high rates of psychosocial difficulties, which are likely to have an adverse impact on their capacity for realistic planning and support of their partners in this critical period of adjustment to parenthood. We recommend enhanced models of clinical care in which assessment and provision of support for partners is incorporated in comprehensive care of the pregnant woman with SMI.