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Wild caught shrimp can have a shortened shelf life compared to farm raised shrimp due to handling and on-ship limitations. The loss of freshness in shrimp is partly due to autolytic reactions caused by endogenous enzymes such as polyphenol oxidase. The objective of this study was to determine the effect of sulfi tes combined with modifi ed atmosphere packaging (MAP) on the shelf life of non-frozen shrimp. Fresh South Atlantic white shrimp were subjected to one of four treatments, no bisulfi te rinse-air packaged, 1.25% bisulfi te rinse-air packaged, 1.25% bisulfi te rinse-MAP (60% CO2, 18% O2, 22% N2) and 1.25% bisulfi te rinse-MAP (36% CO2, 64%N2). The quality and freshness of shrimp was measured by determining total aerobic bacterial populations, package gas headspace analysis, shrimp volatiles (GC-MS), meat pH, nucleotide degradation, and visual analysis. Fresh non-frozen shrimp treated with a combination of sulfi tes and MAP maintained the shelf life of fresh shrimp up to 10 days while shrimp in non-MAP without sulfi te and non-MAP with sulfi te developed black spots within 2 and 6 days, respectively. Both MAP treatments slowed bacterial growth while the MAP with high CO2 and with O2 was more effective in preventing off odors and nucleotide degeneration.