The present study aims at investigating the low cycle fatigue behavior of two fully AISI 1080 pearlitic steels which differed intheir interlamellar spacing (72 ± 15 and 143 ± 32 nm). Low cycle fatigue tests were performed under positive strain control atdifferent total strain variations (0.6% ≤ Δεt ≤ 1.6%). It is shown that both alloys presented an asymmetric stress response anda cyclic softening during the first fatigue life fractions. The tension stress peaks were higher for the fine pearlitic steel thanfor the coarse one but the compression stress peaks were less different. The extrusion–intrusion pairs formed at the externalsurface were more developed for the coarse pearlitic steel. The results suggest that the critical short crack size to propagatein the bulk is much smaller in the fine pearlitic steel which explains the shorter fatigue lives. For both steels, the entire fracturesurface comprised a fatigue propagation zone, a final fully brittle zone separated by a narrow ductile transition zone.