AbstractSensor networks are in a numerous number of applications. However, implementing wireless sensor networks present new challenges compared with theoretical networks. Cooja is the Contiki network simulator. It allows large and small networks of Contiki motes to be simulated; moreover, motes can be emulated at the hardware level. In this paper, we evaluate the accuracy performance of two very well-known localization protocols, namely: fingerprint and centroid protocols using Tmote sky in Cooja. It is worth mentioning that this the first time this study is conducted in Cooja. The results conform to the theory that fingerprint protocol has a better performance than centroid in terms of accuracy when accuracy is quantified.