It remains unclear how the variability of adiposity indices relates to incident HF. This study evaluated the associations of the variability in several adiposity indices with incident heart failure (HF) in individuals with type 2 diabetes (T2DM). We included 4073 participants from the Look AHEAD (Action for Health in Diabetes) study. We assessed variability of body mass index (BMI), waist circumference (WC), and body weight across four annual visits using three variability metrics, the variability independent of the mean (VIM), coefficient of variation (CV), and intraindividual standard deviation (SD). Multivariable Cox regression models were used to generate adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for incident HF. Over a median of 6.7 years, 120 participants developed incident HF. After adjusting for relevant confounders including baseline adiposity levels, the aHR for the highest (Q4) versus lowest quartile (Q1) of VIM of BMI was 3.61 (95% CI 1.91-6.80). The corresponding aHRs for CV and SD of BMI were 2.48 (95% CI 1.36-4.53) and 2.88 (1.52-5.46), respectively. Regarding WC variability, the equivalent aHRs were 1.90 (95% CI 1.11-3.26), 1.79 (95% CI 1.07-3.01), and 1.73 (1.01-2.95) for Q4 versus Q1 of VIM, CV and SD of WC, respectively. In a large sample of adults with T2DM, a greater variability of adiposity indices was associated with higher risks of incident HF, independently of traditional risk factors and baseline adiposity levels. Registration-URL: https://clinicaltrials.gov/ct2/show/NCT00000620 .