The aim of this study was to examine teachers' perceptions and concerns about the implementation of the preschool curriculum developed over 10 years (2005-2015). This paper reports findings from an interpretive case study design in four preschool settings in Tanzania with 12 teachers and 8 parent participants. Data were generated using interviews and documentation. The research focus was on how teachers have implemented the 2005 preschool curriculum. The findings indicate that the implementation of the curriculum was problematic due to teachers' lack of knowledge of a child-centred pedagogy. In addition there were no teachers qualified to work with young children, overcrowded classrooms, poor teaching and learning environments, and insufficient teaching and learning materials and facilities. This study recommends that to improve the current situation and attain quality provision of early education, teachers need to develop their professional knowledge through in-service training. The government policy planners need to provide initial teacher education, professional development, and conducive teaching and learning environments with available resources for effective teaching and learning practices.