Phytopathogenic fungi infesting plants and plant parts can cause significant damage to crops, resulting in huge losses in production. To prevent such damage, there is a need to develop effective fungicides that have curative, preventative, and systemic action to protect cultivated plants and their seeds. However, conventional fungicide formulations have drawbacks such as environmental pollution, high cost, and unsatisfactory performance. To overcome these challenges, combination of fungicides and essential oils are increasingly being formulated as seed treatment formulations. In this study we report the physical stability and efficacy of a seed treatment fungicide formulation containing Trifloxystrobin, Cashew nut oil, and Karanj oil under different storage conditions over a 24-month period. The formulations were studied under heat stability, cold stability, and room temperature storage conditions, and various parameters were analyzed, including active content, suspensibility, pH, particle size, pourability, specific gravity, and viscosity. The seed treatment formulation of Trifloxystrobin 3.5% + Cashew nut oil 15.0 + Karanj oil 22.5 FS (trial 6) found to be stable over the 24-month study period, while also showcasing its high efficacy against soil-borne fungi in Groundnut. The formulation's stability over time makes it a reliable and long-lasting solution for crop protection. Overall, the study highlights the effectiveness and stability of this seed treatment formulation, providing valuable insights for the development of safe and efficient crop protection solutions.