The increased use of fiber reinforced plastics (FRPs) in ship topside structures necessitates the need to understand how such structures respond to fire exposure. For this reason we have characterized the nonlinear, thermo-viscoelastic behavior of Vetrotex 324∕Derakane 510A-40 using tensile loading of laminates. Nonlinearity is observed at elevated stress and temperatures above . The data reduction sufficiently modeled the experimental master-curves over the whole temperature range, but suffered from inconsistencies in the creep data and recovery data, perhaps due to accumulated damage during the creep cycle. Our results indicate that the nonlinear viscoelastic behavior significantly contributes to structural behavior under fire loading conditions.