Worry, a form of repetitive negative thinking, has been studied using the Penn State Worry Questionnaire (PSWQ). The aim of the present study was to assess the dimensionality of the PSWQ, as well as three brief versions, in college students from Lima, Peru. The full PSWQ was administered to 290 participants. In order to achieve that goal, we examined the factor structure and reliability of several models: unidimensional, oblique, bifactor, as well as the brief versions. The results suggest that the PSWQ is an essentially unidimensional measure and it functions better without reversed items. Likewise, brief versions were found to have similarly adequate psychometric properties.