Objective To investigate the effect of intradialytic exercise (IDE) on dialysis adequacy and physical function in elderly patients undergoing maintenance dialysis (MHD). Methods A total of 168 elderly MHD patients admitted to the Tenth Affiliated Hospital of Southern Medical University between January 2022 and June 2024 were enrolled. These patients were randomly divided into a trial group and a control group, with 84 patients in each group. The control group received routine conventional dialysis intervention, while the trial group additionally underwent IDE. The withdrawal rate and reasons for withdrawal from IDE in the trial group were statistically described. After excluding the withdrawal patients in the trial group, the differences in dialysis adequacy, sleep quality, fatigue status, and physical fitness were compared before and after intervention and between two groups. SPSS statistics 27.0 was used for statistical analysis. Intergroup comparisons were performed using t test or Chi-sqaure test depending on data type. Results Among the 84 elderly MHD patients in the trial group, 7 were withdrawn, with a withdrawal rate of 8.33%. After intervention, the trial group exhibited significantly higher single-pool urea clearance (Kt/V), longer distance in 6 min walking test (6MWT), and faster step speed and maximum step speed, and obviously lower scores of Pittsburgh sleep quality index (PSQI) and Piper fatigue scale (PFS) than the pre-intervention levels (P<0.05). After intervention, the Kt/V, 6MWT, normal step speed and maximum step speed were obviously higher while the scores of PSQI and PFS were significantly lower in the trial group than in the control group (P<0.05). Conclusion IDE can effectively improve dialysis adequacy, sleep quality and physical fitness, and alleviate fatigue in elderly MHD patients.