In this study, musculoskeletal disorders, energy consumption and input costs of paddy labors have been studied in cultivation, crop protection, and harvesting rice in Northern Iran, Guilan province. The sample size of the study consisted of 74 paddy workers of the study region. The data were collected through Nordic questionnaire and semi-structured interviews. The results indicated that the labor input energy of cultivation, crop protection, and harvesting were 674.6, 356.8 and 205.9 MJha-1, respectively. The total labor input costs were determined to be 22,860,000 IRRs ha-1. Lower back, back and knees were the most common areas where paddy workers were feeling pain. There were significant differences among the age, working hours and working years of healthy and relatively healthy poor paddy workers (p<0.01). One-fifth of the selected farmers self-reported that their health was at a very poor level. Overall, considering the relatively high costs and the different types of common musculoskeletal disorders related to rice cultivation in this province and also the side effects of using the painkillers in the working season, it is recommended to invest and accelerate the process of mechanization of rice farming in Guilan Province of Iran.