Well-educated staff consists of multidimensional experts, and this staff is one of the strengths of the Finnish day-care system. The aim of this article is to clarify the development of the expertise of those early childhood educators who have qualified as kindergarten teachers. The data consisted of the early educators' stories (n = 80) of their growth towards expertise. The analysis was carried out as content analysis. As the results, four key factors in the process of growth towards expertise were created. According to the informants, personal life history, education, work experience and personal attitudes towards work had been the most influential factors in the process of growth towards their expertise. The working environment both facilitated and hindered the growth of the expert. It is possible to foster educators' professional growth with an individual development plan.