Objective: In Iran, as in most developing countries, agriculture is considered a hazardous industry. Musculoskeletal disorders (MSD) have been shown to be the most common occupational injury among farmers. The present study was carried out among agricultural workers of Fars province, Iran to determine the prevalence of musculoskeletal symptoms and to assess working postures and ergonomic working conditions to identify the major risk factors associated with MSD. Methods: This cross-sectional study was conducted on 1501 randomly selected Iranian agricultural workers with at least 1 year of job tenure. Data were collected using demographic/occupational questionnaire, Nordic Musculoskeletal Questionnaire (NMQ), Quick Exposure Check (QEC) technique, and ergonomic working conditions checklist. Results: The mean age of the participants was 41.39 ± 13.64 years. The results of NMQ showed the highest prevalence of MSD symptoms was related to lower back (59.3%), knees (36.9%), and upper back (36.6%). Indeed, the QEC score was high or very high (action levels 3 and 4) in 83.1% of the farmers. Moreover, the ergonomic working conditions checklist revealed that the participants' "working postures" index had the lowest mean, indicating poor ergonomic conditions, while "hand tools" had the highest mean, indicating proper ergonomic conditions. Conclusions: The results demonstrated the high prevalence of MSD symptoms among Iranian agricultural workers. Elimination of harmful working postures was recommended to improve working conditions.