Student retention remains an ongoing concern for higher education institutions worldwide. In the present study, we examine the predictive utility of identity styles, professional identity and academic commitment to academic achievement. We asked 120 second-year students in the profession of engineering in an augmented degree programme to complete the "Identity Styles Inventory," the "Engineering Identity Factors Inventory" and the "Academic Commitment Scale." We found that a normative identity style predicted professional engineering identity and meaningfulness, which predicted the participants' investments in their studies. Additionally, a diffuse-avoidant identity style negatively predicted professional identity, meaningfulness and satisfaction, which provides empirical evidence of the contribution of identity to academic commitment. None of the variables we studied predicted academic achievement. Our findings are relevant, given current debates on access, equity and decolonisation in higher education, because it suggests that students' sense of identity largely influences whether they feel a sense of belonging at university. Although identity styles and meaningfulness are not significant direct predictors of academic achievement, they probably do have an indirect effect on academic achievement through their direct influence on investment.