The availability of tutors in schools is a privilege and an opportunity to support those students who may be sufficiently far behind the expected level that it is difficult for the classroom teacher to bridge the gap. The challenge for schools is to find ways to guide the work of tutors and teachers to improve chances that supported students can learn the relevant concepts and to use those concepts flexibly in the classroom. This article examines some evidence from research studies suggesting that well-structured tutoring programs in mathematics can be successful. But it also seems that unstructured initiatives, both small and large scale, may have limited value for students. It then argues that tutors may need specific professional learning support and presents suggestions of ways for structuring tutoring sessions that can form the basis of professional learning for tutors.