The present study examined the role of personal relevance of sensory pain-related words in selective attentional processing measured with a modified Stroop task administered to 30 patients with chronic low back pain. A related aim of this study was to introduce the application of multilevel analysis to test the influence of personal relevance on selective attentional processing in this sample. Patients completed the modified Stroop task, as well as a set of self-report measures aimed to assess Fear of Pain, Trait Anxiety, Catastrophizing, Pain Vigilance, and Pain Intensity. The modified Stroop task comprised 33 sensory pain-related words for which the personal relevance towards current concerns was rated afterwards by each participant on a 7-point Likert-type scale. The multilevel analyses did not support the hypothesis that personal relevance of sensory pain-related words interacted with Fear of Pain scores of patients in accounting for reaction times in naming the color of sensory pain-related words. None of the other self-report measures accounted for reaction times in isolation or in interaction with personal relevance. The modified Stroop task does not appear to be a robust measure of selective attentional processing in patients with chronic low back pain. The usefulness of other paradigms, such as the visual dot-probe task, should be explored in examining selective attentional processing in this population.