Knowledge on the ideal conditions for the formation of high quality seedlings is fundamental to guarantee establishment success of crops in a safe and efficient manner. Here, we evaluate the effect of different substrates and irrigation frequencies on the initial growth of parica (Schizolobium parahyba var. amazonicum) seedlings. The experiment was conducted in a greenhouse at the Federal Rural University of Amazônia, Capitão Poço, PA. Several variables were analyzed including seedling height, stem diameter, number of leaflets, shoot dry matter, root dry matter, total dry matter, height and stem diameter ratio, shoot dry matter ratio and root dry matter. We found significant differences in seedling development between the applied treatments, including a significant interaction between substrate type and irrigation regime on seedling height, stem diameter, the number of leaflets and plant growth indices, with the best response for proportions 75% soil + 25% bovine manure and 50% soil + 50% bovine manure. Therefore, the substrates containing organic compounds resulted in a higher quality of the seedlings, while the sand consistently presented the lowest increases in seedling production under the three experimental irrigation frequencies, and thus is not recommended as a substrate for the development of Schizolobium parahyba var. amazonicum.