Unpredictability beliefs are related to an evaluation of inconsistency of oneself, other people, and the world. It emerged on the basis of attachment theory, learned helplessness theory, life history theory, and appraisal theory of emotion. Studies have shown that unpredictability beliefs are associated with negative outcomes such as family unpredictability, causal uncertainty, and trait anxiety. The aim of this research was to adapt the Scale of Unpredictability Beliefs, which was developed to measure the level of unpredictability beliefs, into Turkish, to carry out validity and reliability studies. First of all, the translation study was carried out and the data collection phase was started. A total of 563 people, 445 women and 118 men, aged between 18-30 years (Mean = 21.17, Standard Deviation = 2.06) participated in the study. Participants completed Demographic Information Form, Scale of Unpredictability Beliefs, Retrospective Family Unpredictability Scale, and Brief Symptom Inventory. As a result of the confirmatory factor analysis, the 3-factor structure in the original form was confirmed. The Cronbach Alpha coefficients calculated to determine the internal reliability level of the scale ranged from .76 to .87. Test-retest reliability coefficients ranged from .78 to .87. Based on these findings, it was concluded that the scale is valid and reliable for use in Turkey. Thus, an important measurement tool has been brought into our language to be used in studies to be carried out in Turkey. In addition, the connection between early environment as well as early interpersonal relationships with psychopathologies in adult life have been revealed.