Recent research has demonstrated a relationship between healthcare practitioner beliefs about low back pain and recommendations about activity, work restrictions and work absence. None of the research to date has looked at the relationship between practitioner beliefs and actual behaviour. This study investigated the internal consistency of the pain attitudes and beliefs scale (PABS) and if general practitioner (GP) beliefs about back pain were more predictive of sickness certification for non-specific low back pain (NSLBP) than a general predisposition to sick certify patients with other non-specific conditions (common mental illness and non-specific upper respiratory disorders). Ninty-four eligible general practitioners were invited to participate in the study and data from 83 (88.3%) were included in the full analysis. Evaluation of the internal consistency of the PABS found the biomedical subscale was good (alpha=0.781) but the psychosocial subscale was poor (alpha=0.396) after item elimination both subscales improved; biomedical alpha=0.790, psychosocial alpha=0.602. GP sickness certification behaviour for 1 year was gathered from the Department of Employment and Social Security database. Multiple regression analysis demonstrated that neither the biomedical nor the psychosocial subscale of the PABS predicted the number of sickness certificates issued even after controlling for the time employed as a GP, number of hours worked per week and the number of NSLBP patients seen. Certification for other conditions was predictive of NSLBP certificates issued. These results demonstrate that sickness absences certification for NSLBP is predicted by sickness certification behaviour in general and not by scores on the PABS.