Cytomegalovirus retinitis in the human immunodeficiency virusinfected patient currently requires almost daily and lifelong parenteral ganciclovir therapy. Self-preparation of ganciclovir is not an option in the majority of patients with decreased visual acuity or poor muscle coordination. Therefore, based on current stability data, patients usually receive a 5-day supply of reconstituted drug. This requirement is unfortunately associated with poor patient compliance. If the extended stability of ganciclovir was known, then more efficient regimens for outpatient therapy could be formulated. This study was designed to determine the stability of reconstituted ganciclovir between 7 and 28 days. Ganciclovir diluted with normal saline or 5% dextrose in water to final drug concentrations of 5 or 10 mg/ml was evaluated for stability by highpressure liquid chromatography under different conditions of storage. Samples were stored at both 4°C and – 20°C in polyvinyl chloride bags and at 4°C in ADFuse syringes. Ganciclovir remained stable under these conditions for 28 days. On the basis of these data, we have recommended that patients receive a 2-week supply of reconstituted ganciclovir for parenteral outpatient therapy. We have observed high levels of patient compliance with this regimen and no unexpected progression of retinitis over a 5-month period in three patients who received the drug in this fashion.