Agriculture is the most important sector in the Indian economy. It also plays a significant role in sustaining the security of livelihood for the country's millions of farmers. An expert system (ES) is a computer programme that is designed to emulate the logic and reasoning processes that an expert would use to solve a problem in his/her field of expertise, using artificial intelligence technology. The present study explored the constraints faced by paddy farmers and suggestions for effective utilization of paddy expert system app. The present study was carried out during December 2019 among paddy growers in the Vasudevanallur Block of Tirunelveli district. It was revealed that lack of awareness about the paddy expert system app, lack of updation of new farm problems with solution and lack of update about market price were the major constraints in paddy expert system app. All these constraints can be overcome by implementing suggestions provided by farmers like necessity for mass media advertisements/publicity regarding the app on paddy expert system could enhance the awareness among farmers, recent information about market price, new farm problems should be updated regularly on paddy expert system app. The study results will allow the expert system designers to adjust the content and procedures to match end users' expectation. The extension workers will have to demonstrate and train users in handling and using different mobile apps on expert system available in the public domain.