This study examines whether smartphone exposure influences divergent and convergent thinking, and whether openness to experience moderates these effects. Based on the diffuse attention account, which refers to widely distributed attention, we hypothesized that smartphone presence would enhance divergent thinking while impairing convergent thinking. After preprocessing, a total of 59 participants were included in the study, and they were randomly assigned to either the smartphone present or smartphone absent condition. Divergent thinking was measured using the Alternative Uses Task (AUT), convergent thinking using the Remote Associates Test (RAT), and attention using the Stroop task. Openness to experience was assessed as a potential moderator using the BFI-2 openness items. Results showed that participants in the smartphone absent condition performed significantly better on divergent thinking compared to participants in the smartphone present condition. In contrast, smartphone presence did not significantly affect convergent thinking. Furthermore, openness to experience did not moderate the relationship between smartphone exposure and either divergent or convergent thinking. Exploratory analyses showed that diffuse attention was associated with lower convergent thinking, but not with divergent thinking, and was not affected by smartphone presence. To conclude, these findings suggest that smartphone presence may hinder divergent thinking without benefiting convergent thinking, contrary to the assumptions derived from the diffuse attention account.