Contribution: Internships designed to provide training and an initial period of contact with industry, prior to a computer science engineering capstone project, have a very positive impact on both industry and academic capstone projects. Background: Internships and capstone projects are widely used to integrate work-related learning in computer engineering curricula. Both activities offer numerous benefits for students, industry, and academia. Although their effects have been extensively studied separately, the interaction between them remains unexplored. Research Questions: What is the effect of internships on the development of a subsequent capstone project? Methodology: The hypothesis was that the completion of an internship will have positive effects on several aspects of the capstone projects: (1) improved student competencies; (2) improved capstone project outcomes; and (3) decreased supervision effort. Further, these positive effects were expected to be greater in industry-based projects than in academic projects. The hypothesis was tested through a quantitative study of data collected from 274 computer science engineering capstone projects. A period of time with internships was compared with another period without internships, and differentiating between academic and industry projects. Findings: Internships prior to capstone projects improve student skills in autonomy, technology, methodology, and project management; increase the complexity and technological novelty of the resulting projects; and reduce advisor involvement in practical (technology, execution) and keep-the-project-alive issues, and increase advisor involvement in monitoring student work (meetings, reports, and initial arrangements). This effect was observed in both industrial and academic projects.