Purpose: The purpose of the paper is to determine the relationship between climate variability and the prevalence of malnutrition amongst children under five in Fiji Methods: The study used an ecological study design and used both quantitative and qualitative analysis. The quantitative and the qualitative parts of the paper will complement each other but otherwise remain distinct. Secondary data collection was done to extract malnutrition, climate and the other covariate variables. Trends of climate variables and malnutrition were examined and to determined how they behaved during the study period. A generalised additive model (GAM) using autoregressive integrated over moving averages (ARIMA) as Poisson process was used to determine the association between climate variables and malnutrition. Examination of existing works of literature was also carried out on other factors associated with malnutrition. Findings: The trend of average minimum, maximum temperature and average relative humidity did not vary from January 2006 to December 2016. There were variations in the rainfall trend with high rainfalls in 2008 and 2012. The indicators of malnutrition (underweight, growth faltering, severe malnutrition and anaemia) decreased in the first half of 2011 and increased in the second half of the year. In 2012 malnutrition increased in the half and decreased in the second half of the year. The Fiji Indians had a higher prevalence of malnutrition than the I- Taukei and the other minority race.