Analysis of Gymnopilus purpuratus from two localities in the G.D.R. revealed the presence of psilocybin, psilocin and low concentrations of baeocystin. Psilocybin levels varied from 0.07 % up to 0.33 % of dry weight of the bluing basidiocarps. The psilocin content was high and reached 0.31 % of dry weight. The highest concentrations of the alkaloids were found in the smallest basidiocarps. High levels of psilocybin were found to be correlated with high levels of psilocin and baeocystin. Caps contained more baeocystin than stems; the concentration of psilocin was highest in the stems. Other tryptamines, muscarin and urea were absent from this hallucinogenic species.