The lexicon is one of the most core elements in a language system, so acquiring/learning it is a must-do job for ESL/EFL learners. Nevertheless, whether ESL/EFL learners can employ English lexical learning strategies (LLS) autonomously or not has concerned researchers and educators in different contexts. This study, therefore, endeavors to explore the use of autonomous English LLS by non-English majors at a technical Ho Chi Minh City-based university in Vietnam. It involved 200 students in answering a closed-ended questionnaire and ten students in semi-structured interviews. The results revealed that research participants sometimes utilized LLS autonomously in English language learning. Among five groups of autonomous English LLS, participants sometimes tended to use more determination strategies than other groups of social, cognitive, and metacognitive strategies and memory strategies. Additionally, the results showed that females utilized English LLS more autonomously than males. The findings imply that technical students, especially male students, seemed not to focus much on English LLS.