Embodiments of the present invention provide a method, system and computer program product for telephone call co-processing in a mobile telephony environment. In an embodiment of the invention, a method of telephone call co-processing in a mobile telephony environment is provided. The method includes monitoring a resource state of a selected mobile telephone, such as cellular network signal strength or battery charge. The method additionally includes detecting weakness of the resource state sufficient to inhibit the maintenance of a telephone call in the selected mobile telephone. Finally, the method includes, in response to detecting weakness of the resource state, identifying a different mobile telephone proximate to the selected mobile telephone and utilizing the different mobile telephone to process a telephone call.