This paper presents the validation done on the simulation procedure for a vertical oil/water flow. A 3-D steady state simulation was carried out to predict the behavior of the oil/water flow in the well bore with presence of a hydro cyclone separator. The procedure is then validated against a previous experimental work of oil/water flow in a vertical pipe. The volume fraction distribution profile for the simulation is compared against the profile obtained from the experimental work for three cases of mean volume fraction: 0.068, 0.135 and 0.205. The simulation results for oil volume fraction distribution agrees with the results with error of difference falling below 12. This agreement shown in the results concludes that the procedure applied is acceptable. © 2006-2016 Asian Research Publishing Network (ARPN).