Background/Aim: The relationship between body mass index (BMI) and intradialytic hypotension (IDH) has been inconsistently reported, but no further research has investigated the correlation between body composition and IDH so far. This study aimed to determine whether the lean tissue index (LTI), fat tissue index (FTI), or both derived from body composition monitoring (BCM) is associated with IDH defined as a nadir intradialytic systolic blood pressure of <90 mm Hg and ≥3 episodes hypotension per 10 hemodialysis (HD) treatments in patients undergoing prevalent HD. Methods: The observational cohort study comprised 1,463 patients receiving thrice-weekly HD from 13 dialysis centers. LTI and FTI were assessed using a BCM machine, a multifrequency bioimpedance spectroscopy device. Unadjusted and multivariable adjusted logistic regression models were fit to estimate the association of body composition with the odds of developing IDH. Results: One hundred and seven patients (7.3%) were diagnosed as IDH. The difference in dialysis vintage, BMI, FTI, LTI, high-density lipoprotein cholesterol, and C-reactive protein between IDH and non-IDH groups was statistically significant (all p < 0.05). The prevalence of diabetes among IDH patients was slightly higher than among non-IDH patients. In logistic regression models, low LTI and high FTI, but not high BMI were associated with greater odds of IDH (“high” as above median and “low” as below median). When patients were further stratified into 4 distinct body composition groups based on both the LTI and FTI, only the low LTI/high FTI group was connected with a significantly higher odds of IDH (OR 2.686, 95% CI 1.072–6.734; reference: low LTI/low FTI group). Conclusions: The LTI and FTI can provide better correlation of IDH occurrence than the BMI alone in prevalent HD patients. The low LTI/high FTI appears to be most associated with IDH. An optimal body composition for preventing the occurrence of IDH needs to be determined.