The Millennium Cohort Study is the latest in the line of British birth cohort studies. MCS resembles its predecessors which follow people born in 1946, 1958 and 1970 in the intention to become multi-purpose longitudinal data resource charting many aspects of individual's lives over time. The families of a sample of around 20,000 babies are being interviewed during 2001-02, when eligible babies reach 9 months, to establish the conditions from which they set out in life. The survey contrasts with the previous cohort studies in various ways. Instead of taking all births in one week, the sample of births is spread over a year; the births are from a selection of electoral wards, thereby enabling eventual analysis by neighbourhood characteristics; it also over samples children living in deprived areas, wards with high ethnic minority populations and samples have been boosted in Scotland, Wales and Northern Ireland. The latter UK country has not been covered by the other studies. It interviews fathers as well as mothers, and given that its initial funding comes via the ESRC, puts a greater emphasis on socio-economic data than in early parts of the other studies. MCS has been enhanced by additional Government funding. The research team, based at the Institute of Education, aims to deposit a multi-purpose dataset for public use at the ESRC data Archive in the Spring of 2003.