Since 2000s, official statistical surveys of nonprofit institutions in Italy provide reliable statistics and a detailed picture of nonprofit sector. In order to ensure the availability of time series data, Istat has collected data on nonprofit institutions within the General Census of Industry and Services, in 2001 and in 2011. Crossing the last decades, the Italian National Institute of statistics has been committed in implementing the strategy of permanent censuses, which made possible to have accurate and yearly updated of statistics of nonprofit sector. The innovated surveys allow outlining dimensions and peculiarities of the sector, by recognizing its role and increasingly legitimizing the economic and social development model, which nonprofit institutions represent. Data collected on nonprofit institutions allow to highlight multiple aspects of the sector and to study interesting topics such as the economic and environmental sustainability, the social impact of their activities, the capacity of generating employment and social cohesion, to include vulnerable people, the relations with public and private organizations.