In this study we investigated temporal patterns in activity of adult macro-moths in Colo-i-Suva mixed lowland tropical forest on Fiji's largest island, Viti Levu. Moths were collected for 2 or 3 nights per month over a 12-month period using a mercury-vapor light as an attractant and collecting moths that had settled onto a white sheet for 4 hr after dusk. In total 1,397 specimens were captured, belonging to 116 species in 10 families. There were no significant relationships between total abundance and species richness with any of the climatic factors measured: average minimum and maximum daily temperature, average daily rainfall, and relative humidity. There were no obvious trends in total abundance and species richness over the 12-month monitoring period, although multivariate analysis suggested that moth assemblages in the wet and dry seasons were distinct in terms of their composition. These differences appear to be caused by some of the more-common species exhibiting clear peaks in abundance at certain times of the year, whereas other less-common species were restricted to only dry-season or only wet-season samples. We believe that this study is the first to obtain detailed information on flight periods of adult macro-moths in Fiji. Further research is required to ascertain whether patterns we have observed at this location repeat themselves in subsequent years, and to compare seasonal patterns of moths in other forests, other habitats, and other Fijian islands.