Based on an ethnobotanical survey related to inflammatory diseases, 67Guinean plant species belonging to 35 botanical families were inventoried. Some plant species frequently used in the treatment of rheumatism, skin diseases and microbial infections were selected and submitted to a biological investigation including antimicrobial and anticomplement activities. At a concentration of 1mg/ml, all the tested extracts were devoid of any activity against the tested fungi viz Candida albicans, Aspergillus niger, and Trichophyton rubrum and showed a cytotoxicity varying from 0.25 to 500 µg/ml which prevented the evaluation of possible antiviral effects against herpes simplexvirus type 1, Coxsackie-B2, Measle Edmondston A, Poliomyelitis virus type 1, Semliki forest L10 and Vesicular stomatitis virus for viruses. At 1mg/ml, only the extracts ofAgeratum conyzoides, Alchornea cordifolia, Acanthospermum hispidum, Erythrina senegalensis, Harungana madagascariensis, Hymenocardia acida, and Lophira alata showed an antibacterial effect against Bacillus cereus and/or Staphylococcus aureus. All the tested extracts exhibited an inhibitory effect on the Alternative Complement Pathway complement except for Bambusa vulgaris. Only the extracts of Ageratum conyzoides and Hymenocardia acida interfered with both activation pathways of the complement system. The results of the present work support the anti-inflammatory traditional use of some selected plant species which could be explained, at least partly, by their anticomplement properties.