BACKGROUND: Caring for a baby can provoke or intensify discord between parents, with adverse effects on their own well-being and their parenting. AIM: The aim of this study was to appraise evidence obtained from 450 mothers on the quality of the parents' relationship during the postnatal period and the value of support provided by health visitors in cases of discord. DESIGN: The health visitors were based at nine clinics in an outer London borough, and had been trained on a four-day course (the Brief Encounters course) to screen mothers for relationship problems at the 6-8-week check and to offer support (supportive listening, practical advice, referral) if problems were revealed. Data on relationship quality were obtained by a self-report screening scale completed at the 6-8-week check and again at the 12-week visit for immunizations, when the scale was included in a self-report questionnaire on help received from the health visitor. Intervention records kept by the health visitor showed what form any support had taken. Some 6 weeks later, 25 of the 82 mothers offered support, and their health visitors, were interviewed about their experience of the intervention. RESULTS: One in five mothers were identified as having a relationship problem at the 6-8-week check. Most were offered support. One in five of the 351 mothers who completed a questionnaire at the 12-week visit reported receiving support in improving their relationship. The follow-up interviews showed that most mothers valued this support. Responses to a questionnaire completed by health visitors showed that most were enthusiastic about its benefits. CONCLUSIONS: A four-day training course for health visitors enabled them to screen for relationship problems during the postnatal period and to provide support when required in a way that was valued by mothers. Most health visitors were enthusiastic about the value of the intervention in improving their contribution to family welfare.