The present study is a review of the archaeobotanical analyses carried out in the last decade at the three ancient Roman port/dock system sites of Pisae, Portus, and Neapolis. Pollen, plant macrofossils (leaf, wood, seed/fruit macroremains) and wood constituting the shipwrecks were considered, and the results, partly unpublished, integrated and interpreted. Waterlogged sediments from these port areas turned out to be particularly suited for archaeobotanical analysis and opened new perspectives in ancient harbour studies. This is the first time that a synthesis of archaeobotanical data from Italian archaeological sites of the same typology is attempted for the Roman period. The disparate sampling strategies and available materials for macrofossil analysis in the various sites – cores in Portus, short sediment sequences in Pisae, and single visible hand-collected macroremains in Neapolis – conditioned the results obtained for these remains, making the comparison among sites a particularly difficult task. The urgency of establishing a common protocol between archaeologists and archaeobotanists is thus emphasized. The plant micro-and macrofossils highlight that in Roman times the landscape of the Italian coasts between Pisa and Naples was formed by deciduous oak plain forests (whose relicts are preserved in some protected areas, like in Parco Nazionale del Circeo, south of Rome and along the coast of the Pisan plain, in the Migliarino San Rossore Regional Park) with prevalence of mesophilous elements. The Mediterranean vegetation was not widespread as expected and maquis was limited to small areas by the coast. Surprisingly, mountain elements such as beech and silver fir were not so rare in pre-Roman times, suggesting that these trees could have occupied wider areas than at present. Besides food plant remains typical of the Roman age, the port sediments also preserved seeds, fruits and leaves of the wild vegetation. Comparing the results obtained by palynology with the shipwreck wood study showed that the boats were prevailingly built with local timber, often with conifers. The use of silver fir, though never very frequent, still confirms the preference of shipbuilders for this timber, which was not always available in the close surroundings of the three sites.