Lexical knowledge forms a firm foundation in the second language (L2) learners’ efforts to cope with academic tasks and manage the four language skills. At pre university level, many Malaysian learners struggle with the complexity of content and language. Hence, this study, guided by the theoretical paradigm of cognitivism was undertaken to explore learners’ metacognitive awareness of declarative knowledge, procedural knowledge and conditional knowledge in learning lexical items when preparing for the Malaysian University English Test (MUET). A case study involving participants of varying language ability was carried out to explore how metacognitive awareness is embraced by these learners. Research data was obtained through in-depth interviews and journal records. The results indicate that these Malaysian learners have commendable degree of awareness, particularly in the domain of declarative and procedural knowledge. However, conditional knowledge is seen to be somewhat lacking, particularly from their instructor’s perspective. In order to harness metacognitive awareness and enable learners to become self-directed, instructors need to make conscious decisions to cut back at the right time and let learners be at the forefront in the learning process. It is also vital that instructors know the basic roots and then focus on the advanced concepts, subsequently, making informed decisions on the type of vocabulary and structural items to be imparted, so as to enhance metacognitive awareness of lexical items.