In the present study, we provide evidence on the potential mechanisms involved in the residual pulmonary impairment described in long COVID syndrome. Data highlight that lung damage is significantly associated with a proinflammatory platelet phenotype, characterized mainly by the formation of platelet-leukocyte aggregates. In ex vivo experiments, long COVID plasma reproduces the platelet activation observed in vivo and highlights low-grade inflammation as a potential underpinning mechanism, exploiting a synergistic activity between C-reactive protein and subthreshold concentrations of interleukin-6. The platelet-activated phenotype is blunted by anti-inflammatory and antiplatelet drugs, suggesting a potential therapeutic option in this clinical setting.