We have used the TAURUS Fabry-Perot imaging spectrograph at the William Hershell Telescope of the Observatorio del Roque de los Muchachos to study the kinematics of the HII regions in the central zone of the irregular galaxy NGC 4449. Velocity maps have been obtained in the lines of Hα and [OIII]lambda 5007. Those maps allow us to study the gradient of velocity along the axis of the galaxy, and between the inner and outer regions, as well as the kinematics of the diffuse ionized gas. For each HII region the two observed emission lines were fit with a gaussian profile, and we determined the peak intensity, radial velocity and the line width. We have combined this data with narrow-band images of the galaxy in order to gain insight into the effect of the massive stellar population on the energetics of the ionized gas.