In October 2007, the Italian Ministry of Health, the Centre for Disease Control and the Regions entrusted the National Institute of Health with the coordination of the initiative "Okkio alla Salute"--Promotion of healthy lifestyle and growth in primary school children. This programme is linked to the European programme "Gaining health" and the National Plan for Prevention. The objective of the project was to develop and maintain a monitoring system for both the health services and the schools that could also be used to better target public health interventions. The first national survey to estimate the prevalence of overweight and obesity in children and to collect information on diet and physical activity has been conducted in close collaboration with the individual regions. In the first nine months of the project, 1025 health workers and approximately 1500 school teachers have received training, and, using standardised methods, they have collected data and weighed and measured nearly 45000 third grade students (median age 8.8 years) in 2000 schools throughout the country. Participation rates have exceeded 95%. The results obtained to date indicate that the methodology is sustainable using existing health and educational resources and can be adopted as a national surveillance system.