Thin-layer chromatography confirmed the presence of psilocybin in Psilocybe semilanceata and P. coprinifacies collected in Czechoslovakia. In P. semilanceata , this is the first proof of psilocybin in native fruit bodies. For P. coprinifacies , it is a new finding. The concentration of psychotropic compounds was species-specific and stable. Psilocin was not definitively detected.