A review of 13 birth cohort studies was undertaken to examine the factors associated with successful longitudinal studies across early childhood. The review considered study design, breadth of variables, and factors influencing study quality, productivity and contributions. The studies were found to have contributed to knowledge about health and development in multiple domains and beyond early childhood. Areas identified as the focus for additional data were: child care, rural urban differences, influence of fathers, family factors, peers, social competence, and genetic factors. Data quality was found to be dependent on skilled staff and the ability to track study participants. The most productive studies were long term, had representative samples, ongoing funding and large research teams.