It is well-known that mobility increases the through-put of wireless networks, and the main objective of this paper isto show that, depending on the system’s parameters, delay canactually be negatively impacted. To do so, we study a Markovianmodel where users arrive to the network according to a Poissonprocess with rateλand then move at speedα∈[0,∞)betweennodes while in service.Given the complexity of the model, we resort to approximationtechniques in order to get insight into the influence of the speedαon the mean delay. Our main findings are the following:•in the case where the network consists of two nodes, delayis monotone inαfor small values ofλ. We furthermoreexplicit a constantCsuch that delay is increasing if andonly ifC <0;•in the general case, we provide numerical results showingthat delay is not necessarily monotone inα. However, wecompare the two extreme cases with0and infinite speed,and find that for small values ofλ, delay is worse withinfinite speed than with0speed if and only ifC <0.Finally, an intuitive interpretation of this constantCis provided.