Although a large range of literature on awareness and metacognition focuses on different neurological populations, little attention has been paid to Multiple Sclerosis (MS). This paper gathers literatures related to studies of anosognosia and the theoretical construct of metacognition which both offer a means to operationalize and measure awareness in MS. We focused on both a clinical concern, regarding the relationship between subjective and objective evolution of cognitive performance, and the theoretical issue of metacognitive processes implicated in disease awareness. We identified 26 papers with findings related to awareness of cognitive impairment in MS using questionnaire-based or performance-based methods. We found support for the idea that the relationship between subjective evaluation and neuropsychological evaluation depends on disease duration and is strongly modulated by other variables, such as mood state. We propose that the metacognitive deficit for memory tasks in this population arises from memory impairment. Finally, we discuss methodological issues, variability in MS patients, and the domain specificity of metacognitive impairment.