The practicum is critically important in initial teacher education. Yet too often, student-teachers are placed in schools where the associate teacher does not understand the mentoring component of their supervisory role. This study explores the impact of a school-university project on the associate teachers' mentoring in the practicum and in their leadership roles in the school. A qualitative case study approach was used to investigate these impacts. Data were collected using focus group discussions. Evidence of the impact of the pilot project include: (i) more explicit modelling of and reflection on pedagogical practices, (ii) enhanced relationships with student-teachers, (iii) increased professional learning for wider school roles and (iv) closer university and school relationships. Arguments are proposed that justify these positive findings and recommendations discussed for the design of programmes to enhance mentoring in the practicum that promote student-teachers' professional learning.