A method, system and a computer program product for processing isochronous data packets in a guest memory of a Virtual Machine (VM) using a virtual USB controller. The virtual USB controller is implemented as a software application running on computer system where the VM is implemented. The virtual USB controller is a software component emulating a physical USB controller. The virtual controller uses chains of isochronous packets processed and stored in the guest memory of the VM. Processing of the isochronous data packets includes allocating a buffer in the guest memory for each isochronous data packet and writing the isochronous data packet to the buffer. According to the proposed method, each VM has its own virtual USB controller. The method allows a number of the VMs implemented on a host operating system of a physical machine to concurrently receive data from various USB end-points by employing the virtual USB controllers.