Though Content and Language Integrated Learning (CLIL) approach is not new to teaching - learning process, yet there is dire need to explore different aspects of CLIL intensively for withstanding results. This paper reviews research in primary, secondary and higher education contexts from 2015 to 2020. A review of methodologies, findings, their impact on teaching - learning process and the assessment criteria used, are discussed. This paper may help to outline CLIL research in European context up till now, highlighting the gaps which need to be explored for enhancing CLIL as a second language acquisition approach through content learning.