The paper attempts to explore the factors affecting the farm mechanization in Nepal, where agriculture is the primary livelihood of most people and the mechanization is crucial for efficient production and productivity. The government has also introduced a separate policy for agriculture mechanization in 2014. A primary data was collected from 300 households and analysed to assess and quantify the determinants of the farm mechanization. A descriptive analysis was carried out for understanding the data and the results were interpreted. Similarly, the multiple regression was executed to assess the factors affecting total investment in the farm machinery. The five different models were specified and compared for the better results. Moreover, to have deeper insight, the farm machinery was categorized into light machinery, heavy machinery and animal power. The results showed that light machinery is an essential part of Nepali farming system. Likewise, the presence of animal power, income per capita, per capita farm area, adaptation due to change in temperature, Household size, Farm area and income are significant determinants for total investment in farm mechanization.