The relevance of Non-Timber Forest Products (NTFPs) to community members no longer needs to be proven; these resources contribute mainly to nutrition and health care in many rural areas in Africa. This study aims at identifying medicinal plant species subject to tree bark commercialization in the Lokoli swampy forest and its surrounded farmlands located in southern Benin (West Africa). We analyzed the economic profitability of medicinal tree bark. Three groups of collectors were identified: G1 sells bark locally (G1), G2 at medium-distant markets (< 50km) and G3 at distant markets (> 50 km). We identified a total of 17 medicinal plant species belonging to 13 families of which 11 tree bark species were commonly recorded: Anogeissus leiocarpa, Bridelia ferruginea, Khaya senegalensis, Kigelia africana, Lannea acida, Maranthes polyandra, Nauclea diderrichii, Parkia biglobosa, Pterocarpus erinaceus, Syzygium owariense and Terminalia glaucescens. The net income as well as the economic profitability depended on the group to which collectors belonged. Bark collectors make returns from 31.7±5.45 to 319.0±26.35$ US, annually. The economic profitability ranged from 23% to 54% of the invested costs. The break-even point and safety margin were higher for G3 than G1 and G2 collectors. Similar results were registered for net income and profitability. The most valuable tree bark species were K. africana, M. polyandra, S. owariense, and K. senegalensis.