We report our experience in developing and implementing a training programme aimed at introducing neonatal screening to health care professionals in developing countries. It was originally envisioned as a 10-year programme but was later extended to 15. Our institute initially began offering the training course in neonatal screening on an annual basis in 1990, under the auspices of the Japan International Cooperation Agency (JICA). The aims of the programme were to enhance the participants’ technical knowledge and skills, as well as deepen their understanding of the principles involved in neonatal screening. Over the 15 years that the programme ran, up to March 2005, a total of 130 participants originating from 36 countries completed the course, the participants comprising some 85 paediatricians, 4 obstetricians, 34 biochemists and 7 administrative officers or public health specialists, a number of whom have subsequently implemented neonatal screening programmes in their respective institutes, regions or countries. Having thus completed the initial 15-year phase of the training course, after a thorough evaluation we initiated the second phase of our international training and support programme for neonatal screening in 2006. With the objective of supporting the establishment of a neonatal screening system for congenital hypothyroidism, the new programme consists of not only specialist training in Japan but also financial and technical assistance for helping to establish neonatal screening in the participants’ respective countries.