This study aimed 1) to investigate the behavior of farmers in using agricultural machinery for rice harvesting, 2) to analyze political and economic factors affecting the application of agricultural machinery for harvesting agricultural products, and 3) to propose a guideline for relevant agencies in procuring or recommending suitable agricultural machinery to farmers. The sample group included 450 rice farmers who use agricultural machinery to harvest rice in Chiang Rai Province. The data were collected through interviews and analyzed using descriptive statistics, including variable frequency distribution, percentage, mean, and Chi-Square test to determine the correlation. The study revealed three main findings. First of all, most farmers use agricultural machinery, mostly Kubota brand, for harvesting rice because it saves labor costs. They asked the information about agricultural machinery from their neighbors to make a decision to buy one. Those who did not own any harvesting machine had to rent one from another farmer, which incurred higher costs. Secondly, regarding the factors influencing their decisions to use harvesting machines, farmers prioritized personal factors, followed by the machine efficiency, marketing, and social and cultural factors, with significance levels of 4.22, 4.20, 4.19, and 4.08, respectively. Thirdly, government agencies or other relevant agencies involved with procuring harvesting machinery for farmers should ask about their needs and take a field survey to understand the farm condition to select the machine sizes and types suitable for the area.