Abstract Background The total kidney volume (TKV) and total liver volume (TLV) increase and renal function decreases progressively in patients with autosomal dominant polycystic kidney disease (ADPKD). Somatostatin analogues, such as octreotide, reduce these increases in TKV and TLV. The aim of this study was to examine the safety of the short-term administration of octreotide long-acting release (octreotide-LAR) in a small number of cases. Methods Four ADPKD patients with an estimated glomerular filtration rate (eGFR) [ 45 mL/min/1.73 m 2 , TKV [ 1,000 mL, and TLV [ 3,000 mL were enrolled. Two 20-mg octreotide-LAR intramuscular injections were repeated every 4 weeks for 24 weeks. Laboratory and clinical assessments were repeated every 4 weeks, and TKV and TLV were measured by magnetic resonance imaging before and after the study