Nowadays unmanned aerial vehicles (UAVs) have many applications in very different fields: agriculture, photography, filming, sampling, surveillance... and technology is progressing according to the needs of the market. The use of this technology is increasing due to the ease of adding sensors and mechanical devices to collect data where any other traditional methodology would require more cost, time and waste of resources.The aim of this projectis to develop a system based on UAV technology which main task isto take samples from drinking watersources to analyse them later. Thistask isnecessary to evaluate the water quality, and doing so using UAV technology permit to obtain the results by reducing the cost and time, as well as working in places where it would be difficult to do it in the traditional way. Within in this project ithas been designed a water sampler to take samples of 500 ml volume and the hardware and software necessary to control the sampler remotely from another device, by using a microcontroller attached to the aircraft.