Tide gauge data forms the basis for determining global or local sea level rise with respect to a global geocentric reference frame. Data from repeated precise levelling connections between the tide gauges and a series of coastal and inland benchmarks, including a Continuous GPS (CGPS) benchmarks, is used to determine the stability of tide gauges at 12 locations in the South Pacific. The method for determining this stability is based on using a constant velocity model which minimises the net movement amongst a set of datum benchmarks surveyed since the installation of the tide gauges. Tide gauges were found to be sinking, relative to the CGPS benchmark, in Pohnpei (FSM), Samoa, Vanuatu, Tonga, Nauru, Tuvalu, Fiji and Cook Islands (Is); listed in order of their sinking rate. A maximum of-1.01 0.63 mm/yr is computed at Pohnpei (FSM) and the minimum at Cook Is was statistically insignificant. The tide gauge levels were rising, relative to the CGPS benchmark in Solomon Is, Manus Is (PNG), Kiribati and Marshall Is, with a maximum of 3.12 0.49 mm/yr at Solomon Is and a minimum at Marshall Is, which was statistically insignificant. However, these estimates are unreliable for the Solomon Is and Marshall Is, which have recently established CGPS benchmarks and have been surveyed less than 3 times. In Tonga and Cook Is, the tide gauges were found to be disturbed or affected by survey errors whereas the Vanuatu results were affected by earthquakes. It was also found that the constant velocity model did not fit the observations at the tide gauges in Tonga, Cook Is, Fiji, Marshall Is and Vanuatu, which had large variations in their velocities. This is an indicator of the high frequency (short period) motion of the tide gauge structure, which cannot be measured by the levelling method since they have a higher frequency than the time interval between levelling surveys.