<b><i>Background:</i></b> The outcomes of intragastric balloon (IGB) placement to achieve weight loss in obese patients with chronic kidney disease (CKD) have not been reported to date. This study aimed to assess the safety and efficacy of the IGB as a weight-loss treatment among this patient population. <b><i>Methods:</i></b> A prospective, single-arm, ‘first in CKD' interventional study was conducted in patients with a body mass index >35 kg/m² and CKD stages 3-4, referred for weight loss. After clinical assessment, the IGB was endoscopically inserted into the stomach and kept in place for 6 months. Complications, adverse events, acceptability, weight loss and metabolic responses were monitored over 6 months. <b><i>Results:</i></b> Eleven participants were recruited over 18 months. Two patients withdrew (1 prior to IGB insertion and 1 early removal after 3 days due to persistent vomiting) from the study; 9 patients completed the study. There were 5 episodes of acute kidney injury (AKI), occurring in 3 patients. After 6 months, the mean body mass decreased by 9.6% (SD ±6.8). Median waist circumference and total cholesterol decreased significantly (-7.7 cm; interquartile range (IQR) -15.3 to -3.9; and -0.2 mmol/l; IQR -0.6 to -0.05, respectively), with no changes in estimated glomerular filtration rate, blood pressure, triglycerides, adipokines, inflammation, or arterial stiffness measured by carotid-femoral pulse wave velocity. At IGB removal, there was 1 new case each of gastritis and esophagitis. <b><i>Conclusions:</i></b> Treatment with IGB has only moderate efficacy on weight loss; yet it results in a high rate of complications in obese patients with established CKD. The risk of AKI may be raised due to increased risk of dehydration secondary to gastrointestinal symptoms associated with IGB placement and reduced baseline kidney function.