Two 11-year-old female sibling Pallas cats (Otocolobus manul) were diagnosed with bilateral polycystic-like renal disease. The first case presented in June 2013 with a history of anorexia and lethargy. On exam, the cat had bilaterally palpable renomegaly, with the right much larger than the left. Bloodwork and urinalysis were unremarkable, excepting a relative eosinophilia. Multiple bilateral renal cysts were noted on ultrasound, were drained, and were confirmed cytologically. The cat was treated supportively and improved clinically. The sibling was immobilized and confirmed to have cysts as well, with otherwise normal diagnostic and examination results, also excepting a mild relative eosinophilia. The SSP veterinary pathologist indicated that other Pallas cats had been reported with bilateral renal cysts (some related to these two cats), with none still alive. Over the course of the next 1.5 years, both cats were routinely immobilized for monitoring and cyst drainage. In May 2014, the first cat had cytology consistent with cystic hematomas. Routine cystic drainage was stopped. In November 2014, the first cat presented clinically as in June 2013. A stomach full of pine needles was noted and a gastrotomy was performed. The right kidney was abscessed, so a nephrectomy was also performed. Pathology confirmed hematoma and abscessation with secondary tubulointerstitial nephritis. The first cat improved dramatically, although now consistently has a mildly elevated blood urea nitrogen value. The initial relative eosinophilia was never repeated in either cat. The second cat has never shown clinical manifestations since diagnosis. Both cats continue to be regularly monitored.