This paper explores the use of anticipatory it patterns (such as it is found that and it is necessary to) in English abstracts written by Brazilian graduate students from the disciplines of physics, pharmaceutical sciences and computing as opposed to abstracts of published papers from the same disciplines. The primary purpose is to investigate potential differences between the two corpora with respect to the forms (lexical and grammatical patterns) and rhetorical functions of anticipatory it patterns. The data are drawn from two separate corpora of English abstracts. One corpus is made up of 189 abstracts (40,278 words) written by Brazilian graduate students from the abovementioned disciplines. These abstracts were collected in nine courses on academic writing offered between 2004 and 2009 by the relevant departments of a Brazilian university. The other corpus consists of 1,086 abstracts (187,619 words) which were taken from papers published by various leading academic journals. It has been designed to match the specifications of the corpus of students’ abstracts in terms of disciplines and percentages of texts in each. Striking differences are found between the two corpora in relation to both the lexical and syntactical features of it-patterns and the rhetorical motivations behind their selection. The study also indicates that different disciplines draw on different variations of the pattern but, in many cases, students do not seem to comply with disciplinary conventions.