- This work was carried out to evaluate the influence of thermal stress on the performance of stevia seeds. It was used an accelerating ageing test with temperature of 40°C during 0 (control), 12, 24, 36 and 48 hours to stress replicates of 200 seeds from one Iot harvested in a greenhouse. The frequencies of seed germination were evaluated at each interval of 12 hours during a germination test. The combination between each data set and the parameters from a Weibull function with three parameters were evaluated. After 12 hours of ageing there was an increase in the acceleration of germination and after 24 hours there was a decrease in both the ?hisk? of seed germination and the acceleration. The performance of the seeds from each treatment were different.