In this work, we propose a scale for evaluation of physical activity in young children. The process of developing the evaluation scale was divided into three parts. In part I, we decided the items of the scale. Utilizing questionnaires that had been completed by 152 kindergarten and daynursery teachers, we formalized the concept of the "active child" by classifying the answers into 56 items under 3 main categories and 9 sub-categories. The 23 most relevant items were selected preliminarily to be part of the evaluation scale. In part II, a new questionnaire based on the 23 selected items of the evaluation scale was elaborated and distributed to another group of 54 kindergarten and day-nursery teachers. Each teacher observed and evaluated the physical activity of 6 children, to give a total number of 324 children observed. From analysis of the data collected in part II, we divided the concept of physical activity into four factors : F1, Playing; F2, Leadership; F3, Challenge; F4, Socialization. Based on these factors, our scale was finally adjusted to contain 15 items. In part III, we examined the reliability and validity of the evaluation scale. First, we performed the same test in the same group twice. We analyzed the internal consistency of the factors, as well as the interrelationships among the factors in both tests. The results confirmed the high reliability of the scale. Also, in order to examine the validity of the proposed scale, we collected data from 114 children who wore pedometers to monitor their steps and total daily energy expenditure. We found a significant correlation between the collected data and the total points assigned for each factor in the scale test. We also performed a confirmatory factor analysis whose results validated the method used to construct this evaluation scale. The evaluation scale proposed in this work can be used to verify the effectiveness of a program to increase the physical activity of young children, as well as helping to clarify what causes a child to have low physical activity.