In finding out the nature of cohesion in L2 writing, the present study set out to address three research questions: (1) What types of cohesion relations occur in L2 writing at the sentence, paragraph, and whole-text levels? (2) What is the relationship between lexico-grammatical cohesion features and teachers’ judgements of writing quality? (3) Do expectations of cohesion suggested by the CEFR match what is found in student writing? To answer those questions, a corpus of 240 essays and 240 emails from college- level students learning English as a foreign language in Ecuador enabled the analysis of cohesion. Each text included the scores, or teachers’ judgements of writing quality aligned to the upper-intermediate level (or B2) as proposed by the Common European Framework of Reference for learning, teaching, and assessing English as a foreign language. Lexical and grammatical items used by L2 students to build relationships of meaning in sentences, paragraphs, and the entire text were considered to analyse cohesion in L2 writing. Utilising Natural Language Processing tools (e.g., TAACO, TextInspector, NVivo), the analysis focused on determining which cohesion features (e.g., word repetition/overlap, semantical similarity, connective words) predicted the teachers’ judgements of writing quality in the collected essays and emails. The findings indicate that L2 writing is characterised by word overlap and synonyms occurring at the paragraph level and, to a lesser degree, cohesion between sentences and the entire text (e.g., connective words). Whilst these cohesion features positively and negatively predicted the teachers’ scores, a cautious interpretation of these findings is required, as many other factors beyond cohesion features must have also influenced the allocation of scores in L2 writing.