This paper investigates the causes and impact of students’ misreading of ST vocabulary on their translation in exams. For example, seeing “lake” as “lack” or “surrogacy” as “surgery”, while reading the ST for initial comprehension, can lead to grave errors not only at individual vocabulary-item level but at the level of co-text and even the level of the text as a whole. The problem seems that the first reading, while students are assumed to know both forms and should be able to choose the correct reading, can stick in the minds of the students. Accordingly, they make mental “text structure” (macrostructure) while they read, which they later refer to when using the text information for translation. What seems to be happening in this process is that students (readers), while translating, are referring to a text structure with a “rogue element”. In exams, while under pressure to finish their task in a limited time with very little chance for proper revision, students unduly tend to rely on their first reading, which sometimes can be misleading. The strategy opted for by students is usually trying to make sense of their translation by adapting the meaning to fit the general discourse of the text by additions or omissions to suit their interpretations. In this paper samples of fourth year undergraduate students’ errors resulting from misreading of ST vocabulary in mid-term and final exams are discussed and analysed.