BACKGROUND: In light of climate change, health risks are expected to be exacerbated by extreme temperatures. Many studies showed that high and low ambient temperatures are associated with increased short-term mortality risk, but little is known about these risks in Kuwait and the Gulf Region. OBJECTIVE: To examine the dose-response relationship between 24-h average ambient temperatures and daily mortality risk in Kuwait. METHODS: We gathered mortality and meteorological data from 2010 to 2016 in Kuwait. We did a time-series analysis using a negative binomial distribution, and studied the lag effects of temperature with distributed lag non-linear models. RESULTS: A total of 33,574 all-cause non-accidental deaths were analyzed. The relationship was shown to be non-linear. Overall relative risks of death comparing the 1st percentile (10.9 degrees C) and the 99th percentile (42.7 degrees C) to the optimum temperature were 1.67 (1.02-2.73), and 1.65 (1.09-2.48), respectively. Cold effects persisted for 9 days, while the effects of hot temperatures were the highest at lag 0 and only persisted for a week. Adjusting for PM10 and ozone did not change the temperature-mortality estimates. CONCLUSION: Our findings show evidence that there is a statistically significant positive association between temperature extremes and mortality in Kuwait. The evidence has significant implications in assessing climate vulnerability and provides insight into environmental challenges in an inherently hot and arid region.