Gametophytic self-incompatibility can be one of the obstacles to achieving high yields in plum orchards. Therefore, we sought to verify in the field, the occurrence of gametophytic self-compatibility and its influence on the physical characteristics of fruits in Japanese plum accessions. The work was installed at the Research Pole of IDR-Paraná in Ponta Grossa-PR, in 2021, selecting six accesses belonging to the BAG-Ameixa site. The experimental design was completely randomized (DIC) with a split plot (6 x 2), with the plot having six accessions and the subplot having two methods of pollination, induced self-pollination and free pollination, with five replications. For the variables related to the physical quality of the fruits, the DIC was delimited, with the six accessions as treatment and four replicates of five fruits. Data were analyzed using the Rstudio software, applying the Tukey test at the 5% level. The variables observed for self-compatibility were the percentage of apparent and effective fruiting. For the physical quality of fruits, the total mass, seed and pulp, vertical and horizontal diameter, volume, pulp yield and seed/fruit mass ratio were evaluated. Free pollination was higher in the percentage of apparent and effective fruiting, and the genotypes PR-1013 and PR-1095 were the materials that presented the highest percentages for these variables, as well as for the physical quality of the fruits. The evaluated accessions were considered self-incompatible for not having fruits that reached the final maturity, being free pollination the best method of pollination for the development of fruits.