Anosognosia is a neuropsychological description of unawareness or denial of impairment. Anosognosia for memory disorder (AMD) is a common, though poorly understood, sequelae of acquired brain injury (ABI). Many theories have sought to characterise the neurological, cognitive and motivational bases of anosognosia for hemiplegia, though there are few theories specific to AMD. The studies have largely failed to identify consistent neuroanatomical correlates or types of dysfunction. This has led to the conclusion that anosognosia is a complex multidimensional clinical phenomenon that requires subtle elaboration. Part of the conceptual difficulty has been a function of the relative primitiveness of models of awareness and the tendency for different indices of anosognosia to measure different characteristics of the disorder in an unsystematic way. Recent candidate models of anosognosia have distinguished between deficits in metacognitive knowledge of memory disorder and deficits in online awareness (emergent and anticipatory) of amnesia-related errors. We examined 14 patients with ABI and 15 healthy controls using a multidimensional approach that included a structured interview to assess the metacognitive knowledge aspects of anosognosia and several experimental measures to assess the different aspects of impaired online awareness. Results indicated that different patients could be classified as anosognosic according to which measure was used and that patients could be located on a spectrum of anosognosia which varied along axes of partiality and specifity. The results suggest that despite anosognosia, patients can improve their awareness across learning trials though further research is required to substantiate this. It is hoped that studies such as this, which strive for a developmental reciprocity between theory and service-based practice, may contribute to a more pragmatic understanding of AMD in patients with ABI.