Complementary therapies are increasingly integrated into hospice care, emphasizing the need to examine the evidence regarding implementation and effects on end-of-life outcomes. This review synthesizes the evidence regarding the implementation of complementary therapies and effects on end-of-life outcomes in hospice care. Whittemore and Knafl’s five-step integrative review process was applied. Using predefined search terms, research-based articles between 2006 and 2020 were reviewed. Twenty-three quantitative/mixed method studies conducted across eight countries met the final review criteria. Most commonly used complementary therapies were music, biofield therapies (reiki, therapeutic touch), and massage therapy. Most studies reported significant findings on physical symptoms (pain, dyspnea, fatigue, gastrointestinal symptoms, agitation) and/or psychosocial/spiritual symptoms (anxiety, depression, spirituality, well-being, quality of life); 40% of studies had both significant and nonsignificant findings. Methodological limitations included study design (few randomized controlled trials), small sample size, high attrition rate, lack of racial/ethnic diversity, unstandardized intervention implementation, and multiple outcome measurement instruments. Complementary therapies are promising components of hospice care; however, rigorous studies are needed to validate the effect on end-of-life outcomes and determine the most efficacious implementation. Complementary therapy studies face challenges consistent with end-of-life research; however, efforts to design rigorous trials and address methodological issues are required to enhance the state of the science.