We investigate the use of network coding for information dissemination over a wireless network. Using network coding allows for a simple, distributed and robust algorithm where nodes do not need any information from their neighbors. In this paper, we analyze the time needed to diffuse information throughout a network when network coding is implemented at all nodes. We then provide an upper bound for the dissemination time for ad-hoc networks with general topology. Moreover, we derive a relation between dissemination time and the size of the wireless network. It is shown that for a wireless network with N nodes, the dissemination latency is between O(N) and O(N^2), depending on the reception probabilities of the nodes. These observations are validated by the simulation results.