The prognosis is considered an indispensable tool that assists in understanding various factors that compose forest dynamics, having been employed in various analyses, from projecting production in sustainable management to evaluating prosperity in restored communities. The objective of this study was to validate the prognosis carried out in the Green Belt of the Federal University of Goiás, Goiânia-GO, seeking to verify its accuracy, considering both the estimated diameter structure and the total number of individuals in each class. The prediction was based on probabilistic functions of mortality, recruitment, and growth over time periods between two inventories conducted for data collection, considering the environmental characteristics and forest management employed during this interval, using the movement ratio method. The validation census was conducted in the first semester of 2023, obtaining the values of diameter and standard height of the individuals that compose the Green Belt. After analyzing the data and plotting the diameter structure, a significant increase in the number of individuals in the smaller size classes was noticed, compared to both the previous inventory and the prognosis made, maintaining the estimate of an "inverted J-shaped" structure for the year 2023. KEYWORDS: Diameter classes. Forest dynamics. Movement ratio method.