Internationalization of university curricula is the main reason why the number of bilingual teaching practices (BTPs) in university courses is on the rise around the world. This article reports the perceptions of this type of practice from 70 science students (43 females and 27 males, 17-24 years old) from a Colombian university. A questionnaire was designed, adapted and applied specifically for this investigation. Three major findings were arrived at: (a) a significant percentage of participants perceived that "readings in English" is the most common BTP assigned by their Biology and/or Microbiology course professors. However, a high number of participants perceived that "lectures conducted in English," "written tasks," and "oral presentations" in English were not very common in their Biology and/or Microbiology courses. (b) An "Online translator" (e.g., Google Translate™) is the most common bilingual science study technique (BSST) used by participants, and (c) the majority of participants perceived that the English language plays a key role in the professional development of biologists and microbiologists. Educational implications are discussed.