Background: Family caregivers (FCGs) of adult cancer patients (ACPs) are typically involved in the entire trajectory of cancer disease, from diagnosis to survivorship or end of life. In developing countries, FCGs are more intensely involved in the process of providing care to the hospitalized ACPs because of lack of adequate cancer care resources. Active performance of tasks to meet the needs of ACPs in the hospital setting is likely to elicit significant caregiver burden.; Objective: The aim of this study was to explore the tasks performed and the caregiver burden experienced by FCGs of hospitalized ACPs in a sub-Saharan country.; Methods: A cross-sectional descriptive design was used to collect data from 168 FCGs of ACPs. The Caregiver Burden Scale was used to measure burden.; Results: The most common cancer diagnosis in male and female ACPs was Kaposi's sarcoma (32.1%) and breast cancer (37.9%), respectively. The tasks regularly performed by most FCGs for the ACPs were providing emotional support (79.8%), feeding (68.5%), transporting to other appointments (62.5%), preparing meals (55%), and giving medications (46.4%). Most FCGs (75%) were experiencing severe or very severe general caregiver burden. The dimensions of caregiver burden that were most severely impacted were general strain (70.6%), disappointment (85.8%), and isolation (72%). Predictors of caregiver burden are reported.; Conclusion: Family caregivers of hospitalized ACPs experience severe caregiver burden. The main forms of burden experienced were general strain, disappointment, and isolation.; Implications For Practice: Cancer care services in developing countries should be strengthened with services that address FCGs' emotional needs and human resources to curtail the strain imposed on FCGs.