Nursing is a stressful and highly demanding job. The aim of this study was to investigate the association between psychosocial job strain and the prevalence of back symptoms in nursing personnel using the demand-control model. In a cross-sectional study, 545 nursing professionals answered to a self-administered questionnaire on demography, job content, and lower and upper back symptoms (LBS and UBS, respectively). Based on their answers, the participants were grouped as follows: low strain, high strain, active job, and passive job. The groups were compared in regard to the prevalence of LBS and UBS (totalling 58.5 % and 47.9 %, respectively) over the past 12 months. We found no association between job control and back symptoms, but participants with high psychosocial job demands showed greater risk of LBS (OR=1.57 and p=0.014) and UBS (OR=1.73 and p=0.005) than those with low job demands. LBS in the low strain, high strain, and active job groups was more prevalent than in the passive group (OR=1.64, OR=2.49 and OR=1.90, respectively; p≤0.05). In addition, the high strain group showed greater prevalence of UBS than the passive group (OR=1.82 and p=0.019). Our study suggests that psychosocial job strain, high psychosocial demands in particular, may be associated with greater prevalence of back symptoms in nursing personnel. Our findings may help to design preventive measures that would lower the prevalence of musculoskeletal disorders in this profession.