The aim of the study was to examine the relationship between basketball referees' performance scores gained during a season and their self-efficacy levels. The study was conducted in correlational design and the accessible sampling method was used for the sample selection. The sample of the study consisted of 64 Class-B referees (2% (n=3) were females and 98% (n=61) were males) who actively served in the 2016-2017 season within Turkish Basketball Federation. A demographic information form, "The Referee Self-Efficacy Scale" developed by Karacam and Pulur, and performance scores calculated by the Central Arbitration Committee of Turkish Basketball Federation were used as data collection tools. Data analysis was conducted using SPSS 21 and AMOS programs. The Pearson-Product Moments Correlation Coefficient was used to determine the relationships between the variables. As a result, a positive significant relationship was found between basketball referees' physical fitness, game knowledge, decision-making, pressure, communication, REFS total score, and their performance scores and the variables age and the number of matches refereed. Moreover, a positive significant relationship was found between basketball referees' physical fitness, game knowledge, decision-making, pressure, communication, and REFS total score and their performance scores.