Time series analyses generally rely on having a relatively high frequency of consistent and reliable data to work with. However for many of the South Pacific Island Nations (SPINS), data on major macroeconomic series, like GDP, are typically available only annually from the early 1980s. This paper empirically estimates quarterly GDP data from annual series using the approach of Abeysinghe and Rajaguru (2004), following the basic framework of Chow and Lin (1971), Fernandez (1981) and Litterman (1983). We link the available annual GDP series for a select group of SPINS with GDP-related series (predictor variables) that are available quarterly. We deem that our quarterly estimates of GDP are more consistent and reliable compared to estimates obtained through less sophisticated methods of univariate interpolation.