:Due to the emergence of communication through wireless mode, infrastructure less transmission of data received greater importance. Mobile ad hoc network (MANET) is one such kind of infrastructure less means of communication. Ensuring Quality of Service (QoS) is one of the major research dimensions in the field of MANETs. This paper surveys the review of literature on QoS routing protocols for MANETs. From the review it is evident that on-demand routing is comparatively better than table – driven routing protocols for ensuring QoS. Also it is noteworthy that on-demand routing protocols have more futuristic research dimensions for carrying out further exploration and invention of routing protocols for MANETs.