Background: Informal caregivers (IC) are often overshadowed by the attention required by the terminally ill. This study aims to reveal the estimated proportion of caregiver burden, psychological manifestations and factors associated with caregiver burden among IC in the largest specialized Palliative Care Unit (PCU) in Malaysia. Methods: This was a cross-sectional study involving IC attending a PCU. Caregiver burden and psychological manifestations were measured using previously translated and validated Zarit Burden Interview and DASS-21 questionnaires respectively. Two hundred forty-nine samples were selected for analysis. Result: The mean ZBI score was 23.33 ± 13.7. About half of the population 118(47.4%) was found to experienced caregiver burden whereby majority have mild to moderate burden 90(36.1%). The most common psychological manifestation among IC is anxiety 74(29.7%) followed by depression 51(20.4%) and stress 46(18.5%). Multiple logistic regression demonstrated that women who are IC to patients with non-malignancy were less likely to experience caregiver burden. IC who were highly educated and spent more than 14 h per day caregiving were at least twice likely to experience caregiver burden. Finally, those with symptoms of depression and anxiety were three times more likely to suffer from caregiver burden. Conclusion: Caregiver burden among IC to palliative patients is prevalent in this population. IC who are men, educated, caregiving for patients with malignancy, long hours of caregiving and have symptoms of depression and anxiety are at risk of developing caregiver burden. Targeted screening should be implemented and IC well-being should be given more emphasis in local policies.