Purpose. The objective of this study was to determine the level and rate of change of reaction time during the developmental period from early childhood to early adulthood. Polynomial regression analysis was applied to determine the age at which the best reaction time results are achieved. Methods. The study involved 550 females between the ages of 7 and 20 years. Participants completed a computer test measuring simple reaction times to visual and auditory stimuli and choice reaction time during the ontogenetic developmental period. Results. Analysis of the results for age group distinguished two sub-periods of reaction time dynamics: a progressive increase throughout the developmental period followed by a plateau phase. This was evident for all reaction time measures (simple and choice) particularly in the case of that data collected empirically. Conclusions. best reaction times to visual and auditory stimuli were approximately at the age of 17 years. In turn, quickest choice reaction time was approximately one year earlier in life. The most dynamic increase in the results of both simple reaction times was between the age of 7 and 8 years, whereas for choice reaction time this was between 10 and 11 years of age.