This article describes a case study on native and non-native English-speaker (NES and NNES) students' knowledge and learning of specialized vocabulary over one academic term in a graduate school of theology. After outlining the collection of baseline data on theological vocabulary and the development of a Test of Theological Language (TTL), the article discusses the five NNES and seven NES participants' scores on the TTL. Results on the initial TTL revealed that both groups brought some breadth and depth knowledge of specialized theological vocabulary to their studies, but that the NNES group's scores on both measures tended to be lower than those of NESs. At the end of the term the TTL results indicated an overall increase in scores, but while the gap between the NNES and NES groups in breadth vocabulary knowledge was essentially bridged, for depth knowledge it actually widened. These and other findings are discussed. Test of Theological Language is appended. (Contains 2 tables and 8 notes.)