Data Mining is playing a key role in most enterprises, which have to analyse great amounts of data in order to achieve higher profits. Nevertheless, due to the large datasets involved in this process, the data mining field must face some technological challenges. Grid Computing takes advantage of the low-load periods of all the computers connected to a network, making possible resource and data sharing. Providing Grid services constitute a flexible manner of tackling the data mining needs. This paper shows the adaptation of Weka, a widely used Data Mining tool, to a grid infrastructure.