Anthropogenic carbon emissions released into the atmosphere is driving rapid, concurrent increases in temperature and acidity across the world's oceans. Disentangling the interactive effects of warming and acidifications on vulnerable life stages is important to our understanding of responses of marine species to climate change. This study evaluates the interactive effects of these stressors on the acute responses of gene expression of postlarval America lobster (Homarus americanus), a species whose geographic range is warming and acidifying faster than most of the world's oceans.