Many healthcare facilities (HCFs) in low-income countries experience unreliable connectivity to energy sources, which adversely impacts the quality of health service delivery and provision of adequate environmental health services. This assessment explores the status and consequences of energy access through interviews and surveys with administrators and healthcare workers from 44 HCFs (central hospitals, district hospitals, health centres and health posts) in Malawi. Most HCFs are connected to the electrical grid but experience weekly power interruptions averaging 10 h; less than one-third of facilities have a functional back-up source. Inadequate energy availability is associated with irregular water supply and poor medical equipment sterilization; it adversely affects provider safety and contributes to poor lighting and working conditions. Some challenges, such as poor availability and maintenance of back-up energy sources, disproportionately affect smaller HCFs. Policymakers, health system actors and third-party organizations seeking to improve energy access and quality of care in Malawi and similar settings should address these challenges in a way that prioritizes the specific needs of different facility types.