Introduction: One of the attributes responsible for the good quality of the seedlings is their cultivation on substrates with good drainage and availability of nutrients, where the use of alternative sources of organic matter makes it a strategy for seedling producers. Objective: The objective of this work was to evaluate the initial development of melon when grown in different concentrations of exhausted peat organic compost. Materials and Methods: The experiment was carried out in September 2019, at Faculdades Integradas Stella Maris (FISMA), located in the Municipality of Andradina, State of São Paulo, at geographic coordinates 20°53'26,482"S and 51°22'24,822"W and with altitude approximately 396 meters above sea level. A completely randomized design was used, in a 2x5 factorial scheme, with two varieties of melon (V), namely: Goldmine and Imperial interacting with five concentrations of exhausted peat organic compound (C), that is: zero%; 3%; 6%; 13% and 25% and with four repetitions, totaling 40 plots or plastic vases. Conclusion: It is recommended to use 15% exhausted peat compound in the composition of the substrate in the initial phase of the melon. The melon varieties showed similar responses in terms of exhausted peat compound concentrations.