Smart Irrigation System with DHT11 sensor, Soil moisture sensor and AC motor is an automated system which was designed to increase the productivity of agriculture and control of water consumption. A microcontroller (Arduino) of system plays a major role of control element in the system which continuously sees the environmental conditions and soil conditions. The sensor DHT11 will measure the temperature and humidity of the atmosphere that will influence on the water requirements of crops The soil moisture sensor is the sensor that measures the water content in the soil. When the soil moisture level drops at a specific level established by the parameters, sustain of Arduino the accessories of AC motor linked to water pump is turned spontaneously providing water to the crops. The motor is then switched off so that there is no unnecessary irrigation as soon as the soil attains a good moisture content. This system removes the labor of manual operations, consumes less water, less power and irrigates uniformly. It can be used in farms, gardens and green houses since it is cheap and its design is simple, facilitating sustainable and efficient agricultural activities.