Since the late '60s, the field of second language acquisition (SLA) has grown enormously. Throughout its development, SLA researchers have investigated a wide range of issues including the processes involved in second language learning, as well as the psycholinguistic, affective and social factors that influence its success or failure (Spada, 2014). In light of SLA's relevance and applicability to language teaching, recently a growing number of researchers have taken an interest in second language (L2) learning in classroom settings (Spada, 2014). The term Instructed SLA (ISLA) is currently used to indicate "theory and research that pertain directly to the L2 classroom" (Loewen, 2014, p. 1). One of the main goals of ISLA is to examine which particular types of instruction are more pedagogically effective for a particular learning target. In this short commentary, this question will be investigated in the domain of vocabulary learning. Accordingly, research on instructed vocabulary learning will be briefly reviewed to reveal several insights pertaining to L2 vocabulary pedagogy.