In The Netherlands, periconceptional folic acid use to prevent neural tube defects was promoted through a national 'Folic Acid Campaign'. In two regions, a local campaign supplemented the national campaign to increase the chances of reaching women with low socio-economic status (SES). A framework of outcome criteria, defined as awareness knowledge, perceived safety, attitudes and subjective norms, was developed to evaluate the effectiveness of the two local campaigns. Data were gathered by means of two cross-sectional studies conducted just before and 1 year after the campaigns took place. Before the campaigns were conducted, there were already differences in all effect criteria and folic acid use between women of different educational levels, mostly in favour of women with a high level of education. Although both educational campaigns appeared to have a positive impact on all outcome criteria, they failed to reduce the existing differences in these outcome criteria between women of different educational levels. Folic acid use can be promoted effectively by mass media campaigns, certainly in a large group of women with no prior knowledge of the health benefits associated with periconceptional folic acid use. However, in order to achieve more equal health outcomes among women of low and high SES, it seems that more tailored interventions for women of low SES are needed.