This paper presents an embedded hardware/software architecture specially designed to be applied on mini/micro Unmanned Aerial Vehicles (UAV). An UAV is low-cost non-piloted airplane designed to operate in D-cube (Dangerous- Dirty-Dull) situations [8]. Many types of UAVs exist today; however with the advent of UAV's civil applications, the class of mini/micro UAVs is emerging as a valid option in a commercial scenario. This type of UAV shares limitations with most computer embedded systems: limited space, limited power resources, increasing computation requirements, complexity of the applications, time to market requirements, etc. UAVs are automatically piloted by an embedded system named “Flight Control System”. Many of those systems are commercially available today, however no commercial system exists nowadays that provides support to the actual mission that the UAV should perform.This paper introduces a hardware/software architecture specially designed to operate as a flexible payload and mission controller in a mini/micro UAV. Given that the missions UAVs can carry on justify their existence, we believe that specific payload and mission controller s for UAV should be developed. Our architectonic proposal for them orbits around four key elements: a LAN based distributed and scalable hardware architecture, a service/subscription based software architecture and an abstraction communication layer.