This work aimed to evaluate the vigor (accelerated aging and the seedling length tests) to determine the physiological quality of oat seeds, cultivar UFRGS 14, from the 1996, 1997 and 1998 crops. The germination, seedling length and accelerated aging tests were conducted at the Seed Analysis Laboratory of the Agronomic Institute of Paraná ? IAPAR, in Londrina-PR. The evaluation of emergence in the field was performed at the Experiment Station of IAPAR, in Ponta Grossa-PR. All the evaluations were carried out in December 1998 and March 1999. The experimental design employed was the complete randomized, with four replications, and the means were compared through the Tukey test at the 0.05 significance level. It was concluded that the accelerated aging test is the most effective to detect differences in quality, the seeds being exposed to the temperature of 42oC for 48 hours.