Ultrasonic testing method, due to its very high frequency of stress solicitations, is a very convenient response of the new challenges of which fatigue researches have to cope with. To reach 10 9 or 10 10 cycles is really faster with this type of machines, compared to conventional servo-hydraulic machines. In addition, for many researchers, it is possible to obtain S-N properties of materials by using ultrasonic devices even for high fatigue domain, which is extended from 104 to 107 cycles. This paper deals with a comparison of results from conventional and ultrasonic tests, taken from literature, in the high cycle fatigue domain. A direct comparison and a statistical study have been carried out. Both indicate some divergences between these two methods.