The fate of bubbles formed in tissues during decompression to altitude after diving or due to accidental loss of cabin pressure during flight has only been indirectly inferred from theoretical modelling and clinical observations with non-invasive bubble measuring techniques of intravascular bubbles. In this report we visually followed the in vivo resolution of micro air bubbles injected into adipose tissue of anesthetized rats decompressed from 101.3 kPa to and held at 71 kPa corresponding to approximately 2.750 meters above sea level, while the rats breathed air, oxygen, heliox 50:50 or heliox 80:20. During air breathing bubbles initially grew for 30-80 minutes after which they remained stable or began to shrink slowly. Oxygen breathing caused an initial growth of all bubbles for 15-85 minutes after which they shrank until they disappeared from view. Bubble growth was significantly greater during breathing of oxygen compared to air and heliox breathing mixtures. During heliox 50:50 breathing bubbles initially grew for 5-30 minutes from which point they shrank until they disappeared from view. After a shift to heliox 80:20 breathing some bubbles grew slightly for 20-30 minutes then shrank until they disappeared from view. Bubble disappearance were significantly faster during breathing of oxygen and heliox mixtures compared to air. In conclusion the present results show that oxygen breathing at 71 kPa promote bubble growth in lipid tissue and it is possible that breathing of heliox may be beneficial in treating decompression sickness during flight.