The paper studies the fatigue characteristics of samples of low-carbon low-alloy steels, normalized and cooled from the intercritical temperature range at different rates. Fractographs of the fracture surfaces of the samples after fatigue tests are presented. The fatigue fracture surfaces are analyzed in detail. It is concluded that biphasic ferritic-martensitic steels have a higher resistance to fatigue failure as compared to steels with the ferrite-pearlite structure.