The main purpose of the study was to investigate the prevalence of perceived symptoms of musculoskeletal disorders (MSD) among workers on large-scale dairy and pig farms in Sweden (herd size more than 300 cows and 450 sows) and to identify potential risk factors in the development of MSD. A study based on questionnaires was carried out among 42 workers on 10 large dairy farms and among 37 workers on 10 large pig farms in Southern Sweden during the autumn of 2002. Most importantly, the study showed that 86% of the dairy workers and 78% of the pig workers reported some kind of MSD during a period of 12 months prior to the study. The most frequently reported MSD among both the dairy and the pig workers were in the "upper extremities" (52% and 62%, respectively) especially in the shoulders and in "the back" (60% and 57%, respectively) especially in the lower back. Furthermore, being of short stature, doing repetitive work, working in awkward positions and being exposed to dust were significant risk factors in having MSD among the workers in this study. Thus, working with many cows and sows on large-scale farms in Sweden can be considered as a high risk job with regard to MSD.