In an experiment conducted in the years 2004-2013, the possibility of organic production of the fruit of four cultivars of the Japanese plum (Prunus salicina Lindl.) was evaluated at the Experimental Ecological Orchard in Nowy Dwór-Parcela (central Poland). The studied objects included trees of the cultivars ‘Najdiena’, ‘Shiro’, ‘Vanier’ and ‘Black Amber’ grafted onto Myrobalan seedlings. Under organic orchard conditions, the strongest growing trees were those of the cultivar ‘Shiro’ and the least vigorous those of ‘Vanier’. The highest cumulative yields for the period 2006-2013 were obtained from the trees of the cultivars ‘Najdiena’ and ‘Vanier’. ‘Black Amber’ trees were the lowest-yielding, but the fruits of this cultivar were the biggest. During harvesting, it was found that many fruits had lesions caused by diseases and pests. The extent of the injuries varied depending on the cultivar and the year of the study. The cultivar ‘Vanier’ was the most susceptible to infestation by the plum moth (Laspeyresia funebrana), and the least - the early ripening ‘Najdiena’. Regardless of the year of the study, the highest percentage of decaying fruit due to infection by the brown rot of stone fruits was observed in the crop of the cultivar ‘Vanier’. Among the four cultivars studied, the plum cultivar ‘Najdiena’ characterized by an early fruit ripening time was the most useful for organic orchards.