Papaya is a tropical fruit of great importance in the international and national market. For crop success, the use of quality seedlings is of paramount importance and substrates formulated from organic sources may be a viable alternative. In this context, the objective of this study was to evaluate the initial development of papaya seedlings in different formulations and levels of organic substrates. A completely randomized design was used in a 4x4+1 factorial scheme, corresponding to four substrate formulations, containing decomposed buriti stem (CDB). The treatments included of the following: (CDB, ½ CDB + ½ poultry manure, ½ CDB + ½ cattle manure and ½ CDB + ½ gray with plant origin sourced from materials resulting from the burning of plant material (stem, branches); four proportion levels of the formulations of the substrates mixed to the soil (25; 50; 75 and 100%) and the additional control (100% soil). The following variables were measured: plant height, leaf area, number of leaves, shoot dry matter, root length and root dry matter at 42 days of seedling cultivation. The results showed that use of an ideal source of organic matter is feasible in the production of papaya seedlings. The substrate consisting of CBD + poultry manure had great potential to be used in the production of papaya seedlings.