Contrast‐induced nephropathy (CIN) is a leading cause of hospital‐acquired acute kidney injury, particularly in diabetic patients. Previous studies have shown renoprotective effects of glucagon‐like peptide‐1 (GLP‐1) signalling; however, its role in CIN remains unexplored. This study investigates the prophylactic effect of exendin‐4, a GLP‐1R agonist, against CIN in a rat model mimicking both healthy and diabetic conditions. Animals were randomly divided into 7 groups: a control sham group (n = 8), and 2 identical sets of 3 disease groups, one received exendin‐4 before exposure to contrast medium (CM), while the other served as untreated control. The 3 disease groups represented diabetes (n = 8), CIN (n = 8), or diabetes and CIN combined (n = 8).