Example embodiments relate to work conserving bandwidth guarantees using priority. In some examples, a method may include determining VM-to-VM bandwidth guarantees between a source virtual machine (VM) and at least one destination VM, including a particular VM-to-VM bandwidth guarantee between the source VM and a particular destination VM. The method may include monitoring outbound network traffic flow from the source VM to the particular destination VM. The method may include comparing the outbound network traffic flow to the particular VM-to-VM bandwidth guarantee. When the outbound network traffic flow is less than the particular VM-to-VM bandwidth guarantee, packets of the flow may be directed according to a first priority. When the outbound network traffic flow is greater than the particular VM-to-VM bandwidth guarantee, packets of the flow may be directed according to a second priority.