The design and development of a Web-Based Mushroom Monitoring System with Smart Sprinkler (MMS) for Mushroom House is presented in this study. The system utilizes Internet of Things (IoT) technology and sensor devices to enable real-time monitoring and control of environmental conditions within mushroom houses. The MMS incorporates features such as temperature, humidity, CO2 level monitoring, and smart sprinklers for precise irrigation management. By collecting and analyzing data on environmental conditions and crop performance, farmers can make informed decisions to improve productivity. The study follows the Agile methodology for software development and employs purposive sampling to gather data from IT experts, fungiculture experts, and system end-users. The results show that the MMS offers a reliable and efficient solution for mushroom cultivation, enhancing productivity and resource utilization.