Plasmodia of the true slime molds Physarum polycephalum and Physarum nudum were grown on agar semidefined medium (J. W. Daniel and H. Baldwin (1964) in Methods in Cell Physiology (Precsott, D. M., Ed.), Vol. 1, pp. 9-44, Academic Press, New York.) and pigments were extracted from 8-day-old plasmodia with the same solvent mixture that was used later as a mobile phase in the HPLC analysis. The separation was carried out on a strong anion exchanger column in a methanol/borate buffer solution. Under these conditions eight pigments from P. polycephalum and eight from P. nudum were revealed. This method can be used for detailed studies of plasmodial pigments in these species.