The objective of this research was to determine the level of Mathematical Thought Development that children of five years present. The focus of the research was quantitative of basic type, the simple descriptive method with a non-experimental cross-sectional design was used. The population consisted of 80 children where non-probabilistic sampling was carried out. For data collection, an observation form used as an instrument was applied. The validity of the instrument was made through expert judgments with an approved - applicable result and the reliability was determined through Cronbach alpha. Subsequently, the collected data were processed in the database of the SPSS program. Finally, the results were 64.10% of the children of 5 years are in a process level, while 20.51% is in a level of initiation and 15.38% in the level of achievement, consequently, the predominant level is the process level, which implies raising a higher level of stimulation and reinforcement in order to develop mathematical thinking in the vast majority of children.