Background Primary percutaneous coronary intervention (p-PCI) is pivotal in managing ST-segment elevation myocardial infarction (STEMI); however, it introduces potential risks, such as contrast-induced acute kidney injury (CI-AKI). This study aimed to investigate the relationship between pulse pressure (PP) and CI-AKI incidence in diabetic patients. Methods In this retrospective study conducted between 2021 and 2022, 590 diabetic STEMI patients undergoing p-PCI were categorized based on the presence of wide PP. Individuals with PP >= 65 mmHg were classified as the 'wide PP (+) group', while those with PP < 65 mmHg were classified as the 'wide PP (-) group'. To determine independent predictors of CI-AKI, multivariable logistic regression models were applied. After establishing the base model, blood pressure indices, including PP, SBP, DBP, mean arterial pressure, and pulsatility were added to the model using the stepwise selection method. Results Among the patients, 18.3% (n = 108) were in the wide PP (+) group, while 81.7% (n = 482) were in the wide PP (-) group. The incidence of hypertension, SBP, PP, and the risk of CI-AKI were higher in the wide PP (+) group. Multivariable analysis recognized PP, wide PP, and pulsatility as independent CI-AKI predictors [odds ratio (OR): 1.024, 95% confidence interval (CI): 1.003-1.045, P = 0.025; OR: 1.684, 95% CI: 1.025-2.769, P = 0.040; OR: 13.816, 95% CI: 2.069-92.245, P = 0.007, respectively]. Conclusion Increased PP emerges as an independent predictor for CI-AKI in diabetic patients undergoing p-PCI.