Men as sexual partners, fathers and household heads have a direct bearing on women's reproductive health. However, little is known about the influence of changing norms and values on men's role in ensuring women's health during pregnancy and childbirth. This study from rural south-eastern Tanzania explores men's and women's discussions on men's roles and responsibilities in prenatal care and links them to an analysis of norms and values at the household level and beyond. Data from eight focus group discussions with men and women were consensually coded and analysed using a qualitative content analysis. Four dimensions of norms and values, which emerged from analysis, bear upon men's support towards pregnant women: changing gender identities; changing family and marriage structures; biomedical values disseminated in health education; and government regulations. The findings suggest that Tanzanian men are exposed to a contradictory and changing landscape of norms and values in relation to maternal health.