Background and Purpose. Fear-avoidance beliefs are important determinants for disability in patients with non-specific low-back pain (LBP). The association with self-reported level of physical activity is less known. The aim of the present study was to describe the level of physical activity in patients with chronic non-specific LBP and its relation to fear-avoidance beliefs and pain catastrophizing. Method. A cross-sectional study on 64 patients with chronic non-specific LBP in primary healthcare. The variables measured and the questionnaires used were: level of physical activity (six-graded scale); activity limitations (Roland Morris Disability Questionnare (RDQ)); fear-avoidance beliefs (Tampa Scale of Kinesiophobia (TSK) 13-item and sub-scales ‘activity avoidance’ and ‘somatic focus’); and pain catastrophizing (Pain Catastrophizing Scale (PCS)). The level of physical activity was dichotomised into low and high physical activity. Individual median scores on the TSK and PCS scales were used to group the patients into different levels of fear-avoidance beliefs and pain catastrophizing. Univariate logistic regressions were used to calculate odds ratios for having low physical activity. Results. Patients with low physical activity had significantly higher scores in fear-avoidance beliefs and pain catastrophizing (p < 0.05). Odds ratios for low level of physical activity were between 4 and 8 (p < 0.05) for patients with high fear-avoidance beliefs or medium/high pain catastrophizing. Conclusions. This study indicates that it seems important for physiotherapists in primary care to measure levels of fear-avoidance beliefs or pain catastrophizing. In particular, the two subscales of the TSK could be of real value for clinicians when making treatment decisions concerning physical exercise therapy for patients with chronic LBP. Copyright © 2007 John Wiley & Sons, Ltd.