Traditionally secondary studies on achievement on Programme for International Students Assessment (PISA) tests point to the significant impact of socioeconomic status and cultural backgrounds of families as well as the role of parental involvement, which in some cases has had a negative impact on achievement. For this article, a model of structural regression was tested, with structural modelling software. This model included the following factors: domestic and educational assets, parental support for students, parents' perceptions about science, and science competencies among 214 high performing Mexican students on PISA tests in 2015. This resulted in a structural regression model with a goodness of fit, where science competencies were a positive significant variable, impacted by domestic and educational assets and parental involvement. An additional restricted model with four variables manifested as mediators, revealed that science competencies were predicted positively and significantly by domestic and educational assets, and by the manifest parental emotional support variable. Variables related to ownership of educational and cultural assets and resources, as well as parental support, particularly emotional parental support, have positive and significant impact on science competencies.