The purpose of this study is to assess whether multilinguals' advantage in cognitive flexibility serves as a protective factor against ruminative tendencies common in depressed mood. We compared monolinguals and multilinguals in a backward inhibition task during negative and neutral moods. It was hypothesized that monolinguals compared with multilinguals would perform worse on inhibition trials compared to control when induced into a negative mood. 96 undergraduates from Queens College, a population with high linguistic diversity, were recruited from Psychology 101 courses. Participants were monolingual (n = 47) or multilingual (2+ languages; n = 49). Participants responded to questions about their language and social background before undergoing mood induction to either neutral or negative (sad) affective states. They then completed a computerized cognitive set-shifting task measuring reaction time (RT) and accuracy. A two-way ANOVA was conducted examining the effect of mood condition and mono/multilingualism status on RT and accuracy on the set-switching task for backward inhibition trials. There was a statistically significant interaction between the effects of mood condition and mono/multilingualism on RT, F(1, 92) =6.062, p = 0.002, such that multilinguals had a higher RT compared to monolinguals when induced into a negative mood. The main effects of mono/multilingualism and mood condition were not statistically significant. Difference in accuracy between groups was not statistically significant. Contrary to our hypothesis, bilinguals took longer to respond than monolinguals in a sad mood, specifically for lag inhibition trials. Additional research is needed to determine how sociocultural factors may explain multilinguals' slowed response in a negative mood.