Techniques are described for multicast flow prioritization in protocol independent multicast (PIM) networks with multicast flow limits. According to the disclosed techniques, once a router has reached its multicast flow limit, the router may preempt an installed lower priority multicast flow with a newly requested higher priority multicast flow. For example, if a maximum number of multicast flows are installed on the router, then, upon receiving a PIM join for a higher priority flow as compared to the installed flows, the router replaces one of the installed lower priority flows with the received higher priority flow. Furthermore, according to the disclosed techniques, priority values for multicast flows are consistent across a PIM domain and each of the routers within the PIM domain is configured to use the priority values to select a higher priority flow over a lower priority flow.