A high quality seedling, with vigor superior and balance between growth in height and diameter, may have better survival conditions in the field. The objective was to study different substrates and protected environment on the formation of sweet yellow passion fruit seedlings. The protected environments (agricultural nursery) used were the (A1) agricultural screened (dimensions: 8.0 m x 18.0 m x 3.5 m), closing at 45 degrees tilt, with monofilament black screen throughout its length, mesh with 50% shading (Sombrite (R)) and (A2) agricultural screened (dimensions: 8.0 m x 18.0 m x 4.0 m), with aluminized thermal reflector screen in coverage at 3.30 m, mesh to 50% shading (Aluminet (R)), side and front closings at 90 degrees tilt, with black monofilament screen mesh for 50% shading. Inside the environments, the seedlings were formed on 13 substrates (S) from combinations (%) of cattle manure (E), soil (S), Bioplant (R) (B), super fine vermiculite (F) and sand (A). Emergence, height, stem diameter and the relationship between height and diameter were evaluated. The best passion fruit seedlings were formed on substrates having larger quantity of cattle manure and/or vermiculite, with smaller amounts of sand and Bioplant (R). Substrates with high amounts of Bioplant (R) or sand are not indicated the formation of passion fruit seedlings. The aluminized greenhouse propitiated conditions for obtaining higher quality seedlings with larger diameter in some substrates, and lower height/diameter ratio.