School teachers must be prepared for ongoing, unpredictable and rapid changes in the world, therefore, they need specialised and general knowledge to be able to think independently and imaginatively. The purpose with this article was thus to report on the effectiveness of a self-directed professional development (SDPD) intervention that guided teachers to enhance their curriculum as praxis, especially for 21st-century education. Self-directed learning (SDL) and the capability approach were used to support teachers, through SDPD, to become the teachers they would want to be or could be in the 21st century, in terms of enhancing their curriculum as praxis. Qualitative research was conducted in South-Africa with Grade 9 teachers. Pre- and post-SDPD interviews were conducted, and the SDPD-intervention continued for 3 to 5 months. The results from our research show that the SDPD-intervention effectively supported the participating teachers to enhance their curriculum as praxis.