Researchers suggested that the interruptive effects of chronic pain on cognitive functions may be modulated by the level of pain catastrophizing (PC). However, in individuals with chronic low back pain (CLBP), domains of cognitive function that may be affected by the level of PC remain largely unclear. Therefore, this study aimed to compare cognitive functions between individuals with CLBP with high and low PC and pain-free controls. This cross-sectional study examined cognitive functions of 42 individuals with CLBP and 21 pain-free controls. The PC scale was used to stratify participants with CLBP into high and low PC. Participants performed 5 cognitive tests from the Cambridge Neuropsychological Test Automated Battery, namely 5-choice reaction time, rapid visual processing, spatial working memory, attention switching task, and stop signal task. The statistical analyses revealed that compared with individuals with CLBP with low PC and pain-free controls, individuals with high PC demonstrated greater values of the between errors ( P =0.01), reaction latency ( P <0.001), and stop signal reaction time variables ( P =0.004, 0.003, respectively) but lower values of probability of hit ( P =0.02, 0.01, respectively), A' ( P =0.01, <0.001, respectively), and percent correct trials variables ( P =0.002, <0.001, respectively). The results of the current study showed deficits in sustained attention, working memory, cognitive flexibility, and inhibitory control in individuals with CLBP with high PC. From a clinical perspective, therapeutic interventions targeting PC should be considered to decrease catastrophic thinking about pain in individuals with CLBP. Additional research is warranted to explore cognitive functioning as an outcome of these interventions in individuals with CLBP.