In this study, pupils' understanding of chemical change was investigated in relation to two cognitive variables: logical thinking and field-dependence/field-independence. The participants (N = 99) were sixth-grade elementary school pupils (aged 11/12), which were involved in two different tasks related to combustion. The pupils were tested for their understanding by means of an instrument, where they were asked to describe and interpret the phenomenon. The application of multiple regressions on students' mean achievement score along with analysis of variance demonstrated that the above variables were statistically significant predictors with logical thinking to be the most dominant one. Moreover, a distinction between items emphasizing description and items emphasizing interpretation were made and the effects of the cognitive variables were determined. Path analysis was implemented to depict these hypothesized direct and indirect effects among variables. The findings contribute to the literature by providing empirical evidence that the above individual differences have an effect on pupils' understanding the phenomenon of chemical change at that critical age. Implications for science education are also discussed and it is pointed out that cognitive variables, such as, logical thinking and field-dependence/field-independence should not be ignored in potential teaching interventions. Moreover, theoretical contribution is given by showing that neo-Piagetian theories provide a coherent framework for understanding students' performance in science education.