This study aims to identify risk factors and their prevalence in long-term sickness absence. The study is designed as a case-referent study which comprises 481 participants who have experienced a sickness absence lasting >10 weeks and a reference group of 1326 individuals in active employment. Multivariate analysis identified the following significant risk factors for men: (i) age >50 years [odds ratio (OR) = 2.4]; (ii) short period of education (OR = 2.3); (iii) unemployment within the last 3 years (OR = 1.7); (iv) heavy-duty work (OR = 2.1); (v) monotonous, repetitive work (OR = 1.7); (vi) lack of job satisfaction (OR = 2.1); and (vii) much back pain during the last 3 years (OR = 2.1). The following risk factors were identified for women: (i) leaving school without graduation (OR = 2.6); (ii) unemployment within the last 3 years (OR = 1.5); (iii) heavy-duty work (OR = 2.8); (iv) lack of influence on own job situation (OR = 2.1); and (v) much back pain within the last 3 years (OR = 1.8). It is concluded that the identification of working environment risk factors constitutes a case for improvement of the working environment which may be instrumental in reducing long-term sickness absence.