The main aim of this research is to assess voltage stability problems of the Ethiopian ICS of transmission network. The voltage stability problems in respect of Ethiopian ICS of transmission network have been assessed using continuation power flow and time domain Simulation (dynamic) methods. During the process: transmission line (ICS) data has been collected, data organization has been made and simulation studies have been carried out and analysis of the results has been done. Assessment of dynamic and static margin with respect to SNB, voltage stability margin limit, active power margin limit, and reactive power margin limit of the system during normal operating condition, contingencies, load parameter, fault, and loss of important transmission on the account of voltage stability problems has been made. Buses, where voltage stability could be lost for the maximum power transfer have been identified. Finally, the best solution to the probable voltage stability problems in the high voltage grid has been recommended.