The emergence of multidrug-resistant bacteria has driven the need for novel antibiotics. Our investigations have focussed on lichens as they naturally produce a wide range of unique and very effective defence chemicals. The aim of this study was to evaluate some of the antimicrobial properties of ten common British churchyard lichens. The lichen material was sampled from ten species, namelyCaloplaca flavescens,Diploicia canescens,Cladonia fimbriata,Psilolechia lucida,Lecanora campestrissubsp.Campestris,Lecanora sulphurea, Pertusaria amara f.amara,Lepraria incana,Porpidia tuberculosaandXanthoria calcicola. Crude acetone extracts of these lichens were tested against six bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonela typhimurium, Listeria monocytogenesandLactobacillus acidophilus) and two fungi (Trichophyton interdigitaleandAspergillus flavus) by the disc-diffusion susceptibility test method. Extracts ofDiploicia canescens, Psilolechia lucida, Lecanora sulphurea, Pertusaria amaraandLepraria incanashowed clear inhibition of the Gram-positive bacteria tested (S. aureus, L. monocytogenes, L. plantarum).Diploicia canescens, Pertusaria amaraandLepraria incanaextracts also inhibited the dermatophyte fungi tested. TheLepraria incanasample tested here was the only extract that showed activity against any of the Gram-negative bacteria tested; it showed inhibition ofPseudomnas aeruginosa. Overall, our results showed that crude extracts ofDiploicia canescensandPertusaria amarahad the most potent antimicrobial activity of all the extracts tested. Our results are in general agreement with published findings elsewhere. The activity of thePorpidia tuberculosamargin sample being different from that of the main colony material was an interesting and new finding reported here for the first time.