The experiment, conducted in 2004-2013, assessed the possibility of organic production of the fruit of four plum cultivars. The objects studied were trees of the cultivars: ‘Herman’, ‘Cacanska Rana’, ‘Valjevka’ and ‘Yellow Afaska’, grafted on Myrobalan seedlings. The experiment was established in the spring of 2004 in the Experimental Ecological Orchard in Nowy Dwór-Parcela (central Poland). The trees were grown in accordance with the principles of organic fruit-growing. The plum trees came into bearing fruit in the third year after planting. In the period 2008-2013, the largest amounts of fruit were harvested from the trees of the cultivar ‘Herman’. Other cultivars yielded considerably lower. The lowest fruit yields were obtained each year from the trees of the cultivar ‘Cacanska Rana’. The highest mean fruit weight was found in the cultivar ‘Yellow Afaska’; however, the fruit crops of this cultivar were observed to have the highest proportion of fruit damaged by the plum moth (Laspeyresia funebrana) and infected by the brown rot of stone fruits (Monilinia laxa, Monilinia fructigena). Of the four plum cultivars tested, the most suitable for growing under organic orchard conditions was the cultivar ‘Herman’, characterized by an early fruit ripening time.