Due to the lack of information on the water demand of cocoa seedlings, empirical techniques have been used in the supply of water to the seedlings, potentializing losses in their growth and development. In this context, the present study aimed to determine the optimal irrigation depth for a good development of the genotype PS-1319 cocoa seedlings. The study took place at the Federal Institute of Espírito Santo-Campus Itapina, located in the Colatina, a city situated in the northwestern region of the state of Espírito Santo, Brazil, in an experimental greenhouse of the campus, between October 20 and December 15, 2017. The experiment was conducted in a completely randomized design (CRD) using 20 seedlings of the genotype PS-1319 cacao per treatment. The treatments consisted of daily applications of six irrigation depths, corresponding to 4, 6, 8, 10, 12 and 14 mm d-1, being evaluated their effects on the morphological parameters (leaf area; dry mass of the aerial part, dry mass of the root system and total dry mass; height of the aerial part and stem diameter) and the quality (Dickson quality index). The applied depths interfered, both in the development and the quality of the seedlings, with quadratic adjustments for the leaf area, dry mass of the aerial part and total dry mass, diameter and for the Dickson quality index. The best responses to the studied parameters were provided by the 8.33 mm d-1 depth, which is recommended as an ideal for production of genotype PS-1319 cacao seedlings.