This paper assesses the relationship between EFL proficiency, lexical competence, and collocational competence (cf. Meara 1996; Pawley & Syder 1983; Read 1993, 1997, 2000; Bonk 2001). Two paper-based tests, a proficiency test and a vocabulary test, were presented to English majors at the University of Burundi. Scores on both tests significantly correlate and distinguish between levels. This confirms that lexical competence is a reliable predictor of L2 proficiency, which strengthens and extends earlier findings (Meara 1996; Bonk 2001; Gyllstad 2005, 2007; Zareva et al. 2005). Furthermore, mastery of collocations is found to be related to frequency and to predict lexical competence. Thus, the findings of this study underline earlier indications that proficiency testing may be simplified.