Resumo. Generally, seedling quality is measured only at the nursery, disregarding the main purpose that is the response of these seedlings after planting the field. The study aimed to evaluate the influence of the container volume in the morphological quality of Mimosa caesalpiniifolia Benth. seedlings in the nursery and its survival and initial growth. Five containers (30, 55, 110, 180 and 280 cm ³) were tested, constituting treatments. At 90 and 120 days after seeding, we evaluated height (H) and stem diameter (DC), dry biomass of shoot (MSA), and root dry biomass (MSR), Robustness Index (H/DC), total dry biomass (MST), the relationship between the shoot and root biomass (RMSAR), root density (DR) and Quality Index of Dickson (IQD). After the last measurement, seedlings were field planted. Evaluations consisted in the survival at 120 days after planting, measuring shoot height, diameter at ground level, and calculated the relative growth. Although the seedlings produced in the three larger containers have shown higher morphological quality values in the nursery, it was found that after planting at field this difference tends to disappear, being possible to produce quality seedlings of Mimosa caesalpiniifolia Benth., able to survive, grow and develop after planting, in any of the tested containers.