Decaying grapefruit (Citrus paradisi Macf.) stored under nonventilated conditions caused a substantial reduction in the oxygen and an increase in the carbon dioxide concentrations in the atmosphere. A comparable increase in the internal carbon dioxide concentration of sound fruit in the same container was also observed. Low oxygen caused an increase in the ethanol concentration in the juice of the sound fruit and the development of an undesirable stale flavor. Containment of the decaying fruit in polyethylene film limited the oxygen depletion. Thus, flavor quality of sound fruit from the containers with PE film-sealed decaying fruit was comparable to that of sound fruit stored in the absence of decaying fruit.