Objective This cross-sectional analytic study aimed to investigate the situation of work-related diseases and injuries among cultivated agriculturists in the upper northeast of Thailand. The case study of Udon-Thani and Roi-Et provinces is representative of the upper Northeast region of Thailand.

Methods Cases of work-related diseases reported from the health database (HDC) in 2014–2016 among farmers by occupation code were used for analysis. The number of registered farmers from the agricultural office of Thailand and the secondary data in 43 files of occupational diseases from the provincial public health office were collected from 2014 to 2016. The annual morbidity rate of occupational diseases was analyzed and presented in the rate per 100,000 registered farmers.

Results Chronic lung diseases were the first ranking of disease recorded in HDC among visited farmers for health care in the northeast of Thailand. The following rate of diseases in orders were work-related musculoskeletal disorders (WMSDs), noise and heat-related diseases, and pesticide toxicity, respectively. Occupational injuries were as high as the WMSDs. The morbidity rate of Udon-Thani was higher compared to Roi-Et province, and closer to the national rate. The morbidity rates were increasing every year during 2014–2016 which, in 2016, were 479.1, 207.7, and 26.5 per 100,000 farmers for WMSDs, noise and heat-related diseases, and pesticide toxicity for Udon-Thani database. Those rates were higher than a report in HDC at least 2 times.

Conclusions Situations of work-related diseases among cultivated agriculturists in Thailand were not reflected in reality at the present as underestimation. Two main causes that made the underestimation rate; firstly, the number of cases were rarely reported of ICD-10 as occupational diseases, and the second was an inaccuracy of the number of registered farmers in the population. In the future, all agriculturists should be registered in the agricultural and health database.