The aim of this study was to develop a reliable and valid group test that would evaluate some of the science problem-solving skills of children in grades one, two, and three. The primary grade children used in this study were from three different socio-economic areas: Area I has been described as a low-income urban section; Area II is characterized as a middle-income outlying-urban area; and Area III is a high-income suburban region. The problem-solving skills identified for use in this instrument are: (1) the ability to recognize the problem presented; (2) an understanding of science principles needed to solve the problem; (3) the ability to collect data; and (4) the ability to reason with “if-then” statements. The findings from the preliminary testing were used to clarify ambiguities in test directions and format and to calculate the difficulty and discrimination of each test item. After an item-by-item analysis of student performance, a final form of the instrument was constructed. The data from this final form was used to determine time limits, scoring procedures, test validity, reliability, and norms.