Background Caregivers play a pivotal role in providing care for mentally ill patients. Increase in caregiver burden can make them vulnerable to mental illness themselves.Aims We assessed the severity of burden of care and its association with depression, anxiety and quality of life among caregivers of patients with alcohol use disorder (AUD) and schizophrenia. Methods This was an observational, cross-sectional, single-centred study of 50 consecutive caregivers of patients with AUD and schizophrenia. Participants were recruited from the psychiatry outpatient department of a tertiary care hospital between January and June 2017. The caregivers were further assessed by demographic details, Hospital Anxiety Depression Scale for assessment of depression and anxiety, Zarit Burden Interview for assessment of caregiver burden and WHO Quality Of Life-BREF for assessment of quality of life. Statistical data were analysed using GraphPad InStat V.3.06 (California). Multiple linear regression analysis was applied to identify the predictors of caregiver burden. Results Burden of care experienced by caregivers of patients with AUD is as high as that of caregivers of patients with schizophrenia (U=1142.5, p=0.46). Caregivers experiencing high burden of care are likely to have symptoms of anxiety (U=22, p<0.001), depression (U=32, p<0.001) and poor quality of life (U=84.5, p<0.001). Female caregivers are likely to experience higher burden of care (U=819.5, p=0.006). For caregivers of patients with schizophrenia, anxiety, environmental health, socioeconomic status and patients’ occupation can predict burden of care, while for caregivers of patients with AUD, depression and environmental health can predict burden of care. Conclusion Our study suggests that caregivers of patients with AUD experience burden of care as high as that of caregivers of patients with schizophrenia. Caregivers with high burden of care are more likely to have depression, anxiety and poor quality of life. Trial registration number CTRI/2017/03/008224.