The purposes of this study were to develop and validate an instrument for assessing elementary students' nature of science (NOS) views and to explain the elementary school students' NOS views, in terms of varying grade levels and gender. The sample included 782 students enrolled in sixth, seventh, and eighth grades. Exploratory factor analysis factor structures and confirmatory factor analysis fit indices confirmed the existence of the hypothesised four dimensions in the structure of the nature of science instrument (NOSI). These dimensions and associated Cronbach a reliabilities of scores were observation and inferences (0.74), tentative NOS (0.76), imagination and creativity (0.80), and empirical NOS (0.63). Descriptive analyses revealed that the most favourable NOS views were obtained for the empirical nature of scientific knowledge. The students were uncertain about NOS views related to tentative NOS and imagination and creativity. The least favourable NOS views were obtained for observation and inferences.