The purpose of this study was to uncover pre-service science teachers' images and misconceptions regarding atomic orbital and self-ionization concepts. This study involved a total of 68 pre-service science teachers working at a public university during the 2015-2016 academic year. In this qualitative study, data were collated with the use of worksheets that participating teachers completed by drawing and explain the concepts regarding atomic orbital and self-ionization concepts. Collated data were then subject to content analysis. The results of this study showed that participants' images about atomic orbital and self-ionization concepts were insufficient and that pre-service science teachers hold various misconceptions about orbital and self-ionization concepts. The reasons of the misconceptions could be backed by the pre-service science teachers' inadequacy regarding the mental construction of proper images of scientific concepts and as a recommendation of the study applications are required for improving pre-service science teachers' scientific concepts images being aware of their inadequacy.