This study examined whether and how Zambian preschool education stimulates learning to read. A total of 216 children including 118 with a preschool background were tested at the start of first grade and again approximately eight months later. The Basic Skills Assessment Tool for reading and writing (BASAT) was applied at both measurements. Basic skills at the start of first grade were not better when children had been to preschool but did predict academic success in first grade. Multilevel regression analysis revealed that preschool even had a negative effect on reading and writing at the end of first grade when we controlled for basic literacy skills at the start of first grade. We discuss the use of English in preschool as a possible explanation for the negative effects of preschool.