Objective In patients with chronic pain, catastrophizing is a significant determinant of self-rated pain intensity and disability. The Pain Catastrophizing Scale (PCS) was developed to assist with both treatment planning and outcome assessment; to date, no German version has been validated. Methods A cross-cultural adaptation of the PCS into German was carried out, strictly according to recommended methods. A questionnaire booklet containing the PCS, visual analogue scales (numeric rating scale) for pain intensity and general health, the ZUNG self-rating depression scale, the Modified Somatic Perception Questionnaire (MSPQ), the Fear Avoidance Beliefs Questionnaire (FABQ), and the Roland–Morris (RM) disability questionnaire was completed by 111 patients with chronic low back pain (mean age, 49 years), 100 of which also completed it again 7 days later. Results Cronbach's α (internal reliability) for the three subsections of the PCS—helplessness, magnification, rumination—and for the whole questionnaire (PCSwhole) were .89, .67, .88, and .92, respectively. The intraclass correlation coefficients of agreement for the reproducibility were .81, .67, .78, and .80, respectively. The PCSwhole scores correlated with the other scores as follows: pain intensity r=.26, general health r=−.29, ZUNG r=.52, MSPQ r=.53, FABQactivity r=.51, FABQwork r=.61 and RM r=.57. Factor analysis revealed three factors, with an almost identical factor structure to that reported in previous studies. Conclusion The psychometric properties of our German version of the PCS were comparable to those reported in previous studies for the original English version. It represents a valuable tool in the assessment of German-speaking chronic low back pain patients.