Most research and the development of curriculum interventions relating to girls' opportunities in science education have concerned secondary and tertiary levels. Increasingly, however, evidence and opinions are being reported to the effect that differences between the sexes which appear to be associated with girls' opting out of science already exist when pupils enter secondary education. The encouragement of science and technology in primary schools is frequently proposed as a likely remedy for inequality between the sexes in science education [29, p. 287]. But is this necessarily so? The science education girls now receive leads the vast majority of them to reject it. We must ask what kind of science experience is likely to help and what kind likely to hinder the equal success of girls and boys. We need to know what evidence there is as to the effect of various types of science education and what are the possibilities of expanding access to the better models.