Disparities in college access for underrepresented urban students are one of the most urgent educational problems of America's education system. In response to growing national concern, this longitudinal study investigated how school leaders worked collaboratively with key stakeholders to implement research-supported student services in order to improve college access for underrepresented urban students. The quantitative investigation showed that when educational leaders and key stakeholders worked collaboratively to deliver comprehensive student services, urban students in a high-poverty school district experienced measurable benefits in terms of their college enrolment. This study may be of particular value to policymakers, school leaders, and educators concerned with the low college access rates of students in urban schools, as well as to those who are seeking to understand what works better to prepare urban students for post-secondary education.