Objective:Caring for someone with serious mental illness such as schizophrenia or bipolar disorder can result in considerable consequences for the caregiver. Carers often experience a range of negative emotions, impacts upon their physical and mental health, as well as financial strain. Resultant from these impacts, carers utilise medical services at a higher rate than their non-caregiving counterparts. Further, these consequences of caregiving can also impact upon the patient, resulting in an increase in psychopathology and relapse. Although the notion of burden has been studied for approximately 60 years, many flaws and inadequacies remain; most notably, a lack of agreement on the definition of the construct along with the poor psychometric properties of the burden assessment instruments.Method:This article reviews and evaluates the measures of burden of care that have been utilised with carers of people with a serious mental illness. A systematic search was conducted and all articles that had measured burden of care in schizophrenia or bipolar disorder in the database PUBMED were reviewed to ascertain the measure utilised.Results:Ten different measures were subsequently identified and eight were reviewed; two were excluded on the basis that they had only been utilised once.Conclusions:It was apparent that many of the measures lacked a strong theoretical basis and sound psychometric properties. Further, some of the measures lacked utility, feasibility and specificity. The article concludes with recommendations for future research.