We used RNA-DNA ratios in both field and laboratory experiments to examine the effects of hypoxia on short-term growth of bluegill Lepomis macrochirus collected from the lower Atchafalaya River Basin, Louisiana. In the field experiment, RNA-DNA ratios of bluegill (17.8–52.3 g) from hypoxic habitats (DO < 2.0 mg L⁻¹; n = 26) were significantly lower than ratios of bluegill from normoxic habitats (DO > 4.0 mg L⁻¹; n = 31). In each of two laboratory experiments 40 bluegill (14.54–76.70 g) were individually placed in aquaria to test the effects of hypoxia on RNA-DNA ratios. Additionally, bluegill were fed at different rates in the first experiment to determine the effects of feeding level on RNA-DNA ratios. Results of the first experiment confirmed the sensitivity of RNA-DNA ratios to short-term changes in growth, as fed bluegill had significantly higher ratios than starved bluegill. In both experiments RNA-DNA ratios were not significantly different in bluegill subjected to hypoxia. Results of the study indicate that laboratory experiments did not adequately simulate increased bioenergetic demands and fluctuating DO levels found in hypoxic areas of the Basin.