As temperature changes, many poikilotherms defend membrane fluidity by altering the phospholipid composition of their membranes. This membrane remodeling, coupled with increased oxidative capacity at cold body temperatures, may affect susceptibility to lipid peroxidation (LPO) and necessitate more robust antioxidant defenses. Our study quantifies LPO susceptibility, oxidative capacity, and antioxidant enzyme activity in glycolytic muscle of bluegill, Lepomis macrochirus, acclimated to 5°C or 25°C for 8 weeks. Rates of LPO were quantified in microsomal membranes using thiobarbituric acid reactive substances (TBARS) and C11-BODIPY, a fluorescent lipophilic reporter. Oxidative capacity was determined by the activity of cytochrome c oxidase (CCO), and activities of superoxide dismutase (SOD) and catalase (CAT) represented the antioxidant response. Activity of CCO increases by 1.7-fold in cold-acclimated fish indicating enhanced oxidative capacities. Yet, neither LPO susceptibility, nor antioxidant responses differ significantly between treatments. Support from Ohio University Provost’s Undergraduate Research Fund to DRBM, Peter K. Lauf Travel Award (Ohio Physiological Society) to JMG, and Ohio University Research Committee to ELC.