Background: According to the 2011 U.S. Census 60% of people living in the U.S. speak a language other than English at home, and of these approximately 40% have limited English proficiency (LEP). Language barriers can affect the health outcomes of LEP patients and the use of trained interpreters can improve patient-physician communication. Since effective communication is the cornerstone of delivering adequate palliative care, a systematic review was conducted to determine the impact of interpreters on the delivery of palliative care services to LEP patients with cancer. Methods: We conducted a systematic review of the literature search in all available languages of 6 databases from 1966 and 2013. Studies evaluated interpreter interventions for LEP patients receiving palliative care services. Of 38 references, 11 articles were found by multiple reviewers to meet inclusion criteria. Data were collected on the study design, size, comparison groups, outcomes, and interpreter characteristics. Results: A total of 6 qualitative and 5 quantitative studies assessed the use of interpreters. All studies found that the quality of care provided to LEP patients receiving palliative services is affected by communication. Most studies showed that when no trained interpreters were used, LEP patients and families had inadequate understanding about their diagnosis or prognosis during goals of care conversations, and worse symptom management at end of life including pain and anxiety. Half of the studies concluded that trained interpreters are not utilized adequately and several suggested that pre-meetings between clinicians and interpreters are important to discuss topics and terminology to be used during goals of care conversations. Conclusions: Published studies show worse outcomes during end of life care and goals of care discussions when trained interpreters are not used. Moreover, trained interpreters are not being used appropriately in the field. More clinically relevant studies are needed to improve the quality of care provided to LEP patients and families receiving palliative services.