International government support for free primary education in sub-Saharan Africa has massively increased enrolment in primary schools. One result has been soaring demand for additional primary teachers. To meet this need, a large number of unqualified or underqualified people have been recruited as primary teachers in recent years. Because the quality of primary education is threatened by teachers’ poor qualifications, governments and teachers’ unions alike emphasise the importance of teacher-upgrading programmes. Furthermore, a rise in national teaching standards has rendered many formerly qualified teachers underqualified in the new circumstances. The present study combines a theoretical review with empirical field investigations to identify the lessons learned from teacher-upgrading programmes in Tanzania, Malawi, and Nigeria. The main conclusions are as follows. In-service training is vital to upgrading programmes, both for practical reasons and to enhance contextualised learning and practising. Additional face-to-face contact between student-teachers and their mentors, preferably in teacher development centres close to the teachers’ schools, can provide a professional learning environment for interactive learning. Involvement of both teachers and mentors in the curriculum design is essential to make the upgrading programme effectual in adapting to local circumstances. Special attention must be given to the adaptation of child-centred, participatory teaching methods in classrooms where teaching materials are scarce and pupil/teacher ratios are very high. Success in upgrading depends on sufficient mentoring, the provision of materials for teaching and learning, and capacity building of educational stakeholders at various levels. Continuous in-school evaluation and research, with active participation of mentors and student teachers, can greatly improve the efficacy and ownership of upgrading programmes.