Background and aims: In the current study we have sought to clarify the contribution of metacognitions concerning smartphone use relative to smartphone use expectancies in the relationship between wellestablished predisposing psychological factors and problematic smartphone use (PSU). We tested a model where psychological distress, impulsivity, and proneness to boredom predict metacognitions about smartphone use and smartphone use expectancies, which in turn predict PSU. Methods: A sample of 535 participants (F 5 71.2%; mean age 5 27.38 +- 9.05 years) was recruited. Results: The model accounted for 64% of the PSU variance and showed good fit indices (c2 5 16.01, df 5 13, P 5 0.24; RMSEA [90%CI] 5 0.02 [0-0.05], CFI 5 0.99; SRMR 5 0.03). We found that: (i) when it comes to psychological distress and boredom proneness, negative metacognitions, and both positive and negative expectancies play a mediating role in the association with PSU, with negative metacognitions showing a dominant role; (ii) there is no overlap between positive expectancies and positive metacognitions, especially when it comes to smartphone use as a means for socializing; (iii) impulsivity did not show a significant effect on PSU Direct effects of the predictors on PSU were not found. Discussion and conclusions: The current study found additional support for applying metacognitive theory to the understanding of PSU and highlight the dominant role of negative metacognitions about smartphone in predicting PSU. Kulcsszavak: anxiety, boredom proneness, depression, expectancies, metacognitions, problematic smartphone use