The study addresses the impact of emotional information on the belief bias in syllogistic reasoning. Belief bias refers to the inclination of individuals to make judgments based not on logical principles but on their prior beliefs when evaluating information. Within the framework of this research, a hypothesis was proposed that the emotional content of the syllogism itself influences this tendency: negative emotional stimuli reduce this tendency, while positive emotional stimuli increase it. An original set of stimuli was developed, consisting of 36 congruent and incongruent syllogisms with varying emotional valence (neutral, negative, positive), which were presented to participants in a random order. The results showed that when solving positive incongruent syllogisms, the accuracy of participants decreased, meaning they performed worse on these syllogisms compared to negative and neutral ones. However, no statistically significant differences were found in the solving time for neutral and positive syllogisms. It is important to note that our findings regarding the influence of negative information are fully consistent with previous research results. Specifically, negative syllogisms are indeed solved better and more slowly, not only compared to neutral ones but also compared to positive syllogisms. Nonetheless, considering that our developed experimental procedure has certain limitations, the question of the influence of emotional information on the tendency towards belief bias should be the subject of further research.