Teacher educators play a key role in teacher education and education in general. Worldwide, little is known about preparation and professional development of teacher educators. This paper critically examined teacher educators' preparation and professional development in the context of educational reforms and mushrooming of teacher education institutions in Tanzania. The document review method was used to analyze and review relevant literature. The analysis of findings indicates that the preparation of teacher educators in Tanzania receives considerable attention and focus in undergraduate programmes with little attention in postgraduate programmes. The professional development of teacher educators is limited and characterized by few professional development activities. It is suggested that the preparation of teacher educators should be well structured and enhanced with effective professional development activities and opportunities. Various recommendations to improve the preparation and professional development of teacher educators are also provided.