To improve crop development, commercial substrates are recommended without distinction for different crops and/or varieties without considering their characteristics and needs; therefore, their composition and nutritional condition must be studied for each type of plant in its initial formation.The objective of this study was to evaluate the development of shoot and root systems of two lettuce cultivars produced in 10 different substrates. Great Lakes and Simpson Black Seed cultivars were evaluated in 10 substrates formulated by mixing a commercial substrate, organic compounds (swine, cattle, poultry) and sugarcane bagasse. Great Lakes cultivar had a higher development of the aerial part, whereas Simpson Black Seed cultivar had a more robust root system. The substrate with swine and poultry favored the development of the aerial part of the seedlings and lettuce, while the substrates with 33% of sugarcane bagasse improved the development of the root system. The commercial substrate used in isolation showed the lowest performance.