Cockatiels (Nymphicus hollandicus) are commonly diagnosed with ovarian neoplasia. However, there is very little information regarding medical management of this disease condition and subsequent patient response. Long-term medical therapy of 2 cockatiels eventually diagnosed with ovarian neoplasia is described along with responses to the treatment regimens. Each bird had initial signs consistent with reproductive disease (chronic egg laying, ascites, and lethargy) and respiratory distress. The diagnosis of ovarian adenocarcinoma was confirmed on postmortem examination of both birds. The birds were conservatively managed by periodic coelomocentesis and gonadotropin-releasing hormone (GnRH) agonist administration for 9 and 25 months, respectively. A positive response to GnRH agonist therapy was documented in 1 of the 2 birds. These 2 cases demonstrate that periodic coelomocentesis with or without GnRH agonist therapy may be a viable option for the long-term management of ovarian neoplasia and reproductive-organ–associated ascites in cockatiels.