This study explores the professional learning of ten pre-service teachers from Hong Kong and ten host teachers in a school in China who participated in a teaching abroad project. The participants' professional learning during the project is conceptualised within five knowledge domains of quality teaching for the twenty-first century: personal, contextual, pedagogical, sociological and social. The findings suggest that by immersing pre-service teachers in an unfamiliar teaching environment, they can learn professional knowledge for teaching in an increasingly complex world. This complements the knowledge they are acquiring in their domestic courses and practicums. Furthermore, through the pedagogical exchange of ideas, the host teachers are also found to benefit. We recommend that teaching abroad opportunities be included in initial teacher education (ITE) programmes and that host teachers' professional learning are considered in their development.