Mastery of fundamental movement skills (FMS) is an important factor in preventing weight gain and increasing physical activity. To master FMS, performance evaluation is necessary. In this study, we investigated the reliability of a new observational assessment tool. In Phase I, 110 video clips of children performing five locomotor, and six manipulative FMSs were developed. In Phase II, rating scales were developed, and their efficacy was evaluated by comparing judgments of 30 undergraduate students to a standard. The mean weighted kappa (0.71) was considered good (range 0.51-0.85). Of the 11 rating scales, 6 were modified, and 5 remained unchanged. This study sets the foundation for the development of a new observational scale to assess fundamental movement skills. (Contains 2 tables and 2 figures.)