Abstract: Abstract: Aim  To visually analyze advancements in radiation therapy and the immune microenvironment in rectal cancer, providing a comprehensive overview of literature on the role of various immune cells in radiation therapy, identifying research trends, and highlighting emerging research directions. Methods  A systematic search was conducted using Web of Science Core Collection (WoSCC) to identify articles related to radiation therapy and rectal cancer as well as radiation therapy and the immune microenvironment from 1991 to 2024. Advanced bibliometric tools such as VOSviewer and CiteSpace were utilized to facilitate analysis and describe publication trends, geographic contributions, institutional affiliations, journal prominence, author collaboration, and prominent keywords. Results  First, in the field of rectal cancer radiotherapy, the number of annual publications on adaptive immune cells (B cells and T cells) is the highest compared with the field of innate immune cells, and the number of articles has spiraled up in the past five years. Second, China and the United States contributed the most in these seven areas; whereas authors Kawai, Kazushige ranked first in the field of monocytes and neutrophils. Kitayama, Joji published the largest number of articles in the field of MDSCs and T cells. Third, Rolf Sauer, Claus Rödel and Kitayama, Joji were influential in this field. 
Conclusion  Our bibliometric review offers a comprehensive view of immune microenvironment research in rectal cancer radiotherapy. It summarizes the current status quo while also shedding light on potential future directions for this area of research.