The increasing challenges of water scarcity, labour shortages and climate variability have necessitated the adoption of precision farming technologies in Indian agriculture. Among these innovations, adopting Internet of Things (IoT) technology in agriculture offers significant potential to revolutionize farming methods by increasing productivity, encouraging crop diversification, enhancing sustainability and reducing environmental impact. This study aims to evaluate the perceived benefits and challenges associated with adopting IoT-based smart irrigation systems by farmers in the Coimbatore district of Tamil Nadu. Data were collected from 120 farmers using IoT-based smart irrigation systems, randomly selected from the user list provided by the case firm. The Analytical Hierarchy Process (AHP) was employed to evaluate and prioritize the benefits perceived by farmers. At the same time the Plackett-Luce Model (PLM) was used to identify and rank the challenges that hinder effective usage. Results indicated that environmental advantages, particularly reduced water and energy consumption, were perceived as the most significant. Economic benefits, including enhanced operational efficiency and decreased labour costs, were also perceived as significant outcomes. Additionally, farmers acknowledged personal benefits like real-time monitoring, improved decision-making and reduced physical strain. Despite these advantages, high initial investment, complex user interfaces and limited technical knowledge were identified as the critical challenges encountered by the farmers. These findings suggest the need for affordable, user-friendly and locally supported IoT solutions and targeted capacity-building programs. Addressing these factors is essential for promoting broader adoption and realizing the full potential of smart irrigation technologies for sustainable agriculture.