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Multiple sampling designs are commonly used in forest inventory to combine information collected in very large first-phase samples using remote sensing (satelite or aerial images) with the field data collected on smaller sub-samples. In Italy, during the seventies, double sampling designs were used in some regional forest inventories and, later, multiple sampling was adopted for the second National Forest Inventory and for the Inventory of Forest Carbon Stocks (InFoCarb) in the Province of Trento (Central-Eastern Alps). In this paper the main aspects of the design adopted for InFoCarb are discussed and the results of this inventory are compared with those obtained from the NFI for the same area. The estimates for the above-ground phytomass and the annual increment produced by the two inventories do not differ significantly, while the forest area estimates are significantly different as a consequence of differences in the dates of orthophotos used for the photointerpretation and in the classification procedure.