One of the primary goals in physical education is to get students to begin understanding how to regulate their physical activity. In order to get a better understanding on how children regulate their thoughts toward physical activity that may lead to physical activity, an instrument was designed to examine cognitive monitoring dispositions. Zimmerman's model of self-regulated learning (2000) which is based upon Bandura's social cognitive theory was used as the theoretical foundation for the development of the instrument. The premise of the instrument is to determine the degree of agentic control children may possess for regulating their physical activity behavior. Initial item formulation was based upon a review of literature on physical activity maintenance, adherence and Delphi technique. This resulted in 20 items being formulated. The 20-item instrument was given to 810 fourth grade students in a mid-west community. The instruments were screened for missing data which resulted in 13 instruments being discarded due to missing item responses. Therefore 797 instrument data were input into SPSS v.14 for exploratory factor analysis (EFA). The EFA consisted of Bartlett's Test of Sphericity, principle component analysis for extraction of factors, and varimax rotation. The emergent factors had to meet the following criteria to be included in the model: eigenvalues greater than one and two or more items with a correlation coefficient of .40 or greater. Factor reliability was determined by Cronbach's alpha. The results of the EFA indicated the emergence of two factors meeting the criteria; (a) metacognition, and (b) self-efficacy. The two factors accounted for 46.5 percent of the variance. Nine of the original 20 items were retained in the model; metacognition (5 items) and self-efficacy (4 items). The alpha reliabilities for the two factors were: .657 (metacognition) and .622 (self-efficacy). It was the intent of this pilot study to develop an instrument to examine how children think about the regulation of exercise and physical activity. The concept of thinking about self-regulation is foreign to most elementary children. Therefore, although the explained variance is considered to be low it falls within an acceptable range for the purpose of this study. The results produced a two factor instrument with nine items. The Self-Regulation of Physical Activity Scale (SRPAC) is a parsimonious instrument that taps into how children regulate their physical activity. Future studies will provide a confirmatory analysis of the SRPAC.Keyword(s): assessment, elementary issues, measurement/evaluation