Potato (Solanum tuberosum L.) popularly known as the “King of Vegetables” is a starchy, tuberous crop, that belongs to the family Solanaceae. Potatoes play an important role in the daily human diet because they are a copious source of minerals, vitamins, antioxidants and micronutrient. The potato is a basically temperate crop, but it grows under a wide range of climatic conditions. Potato crop is generally affected by different types of biotic and abiotic diseases. Among all diseases, Late blight of potato, caused by the Phytophthora infestans (Mont) de Barry is one of the most devastating diseases of potato worldwide. In India, the losses caused by the disease are 10-20% in Uttar Pradesh, 10-15% in West Bengal and Punjab, 10-15% in Karnataka and Uttrakhand also have been reported during 2013-14. The management of the disease can be done through cultural, mechanical, use of the resistant variety, biological and chemical, etc. The efficacy of current strategies for the management of disease is limited. Considering the destructive nature of pathogen and lack of efficient control measures, the development of alternative or complementary approaches for the management of this disease is highly desirable. However reported use of the same chemicals may raise resistant strain among the pathogens. Therefore, the use of Nano-fungicidal control of spot blotch disease cannot be overstated. However, the disease can be managed with various nanofungicides under in vitro conditions assessed for their efficacy against the disease. The effect of four nanofungicides i.e., Agritec nanofungicide, Silver nanofungicide, Selenium nanofungicide and Nickel nanofungicide against P. infestance was evaluated at different concentrations (50, 75 and 100 ppm) by poison food technique. The in vitro experiment revealed a noticeable reduction in the radial mycelial growth of P. infestance as the concentration of nanofungicides increased. Specifically, at 7 days after inoculation (DAI), the following nanofungicides at a concentration of 100 ppm exhibited the highest levels of mycelial growth inhibition when compared to the control: Silver nanofungicide (72.45%), Agritec nanofungicide (70.21%), Selenium nanofungicide (68.77%), and Nickel nanofungicide (64.65%).