Development of the Wireless Sensor Networks (WSN) has been promoted by advances in miniaturization, ubiquitous communication, and digital convergence. This technology allows the creation of new applications by implementing of new infrastructure and data acquisition layers. This work presents two applications of WSN supported by the IEEE 802.15.4 protocol; the first one is oriented to monitoring a mushroom crop and the other one to e-health. Both applications are monitoring-oriented, results obtained show how WSN can be used to support requirements of applications for data acquisition in distributed and collaborative way.