Extensive pressure build-up testing was carried out in the gas lift wells of the Falah Field located offshore Dubai. These tests were aimed at gathering reservoir information for input to a three dimensional reservoir simulation model. Pressure testing was carried out using conventional Amerada bombs, downhole memory recorders, and continuous monitoring with a GRC gauge using an electric line unit. Log-log plots of pressure change vs time displayed two different periods of wellbore storage in some wells due to the mechanisms that occurred following shutin. The data was analysed using type curve matching techniques. The radial flow was observed only in two wells. Other wells showed dominance of wellbore storage in spite of long shut-in periods of up to three weeks. The paper presents the results of build-up testing in three wells. The build-up shapes show marked differences due to changes in wellbore conditions.