The dataset reports data from more than 9,000 trees, which were sampled in 2024-2025 to create a first urban tree inventory of public green areas in the Municipality of Arezzo. For each tree, spatial position, species, diameter were sampled in different public green space types. Data are available as table and spatial vector layer. Data can support urban planners and managers for assessing the state-of-the-art of urban greening, supporting tree management practices and monitoring, feeding urban tree models and calibrating remotely-sensed information. Non-spatial and spatial metrics can be derived to assess the diversity of urban tree spaces to implement sustainable urban greening practices. © 2025 Istituto Sperimentale per la Selvicoltura. All rights reserved.