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This paper is aimed at evaluating the influence of bi-modal and lamellar microstructure onthe behaviour of small cracks emanating from notches in the α+β titanium Ti-6Al-4V alloy.Pulsating four points bending tests were performed on double-edge-notched specimens. Theconditions of initiation and early propagation of fatigue cracks were investigated at twonominal stress levels. Crack closure effects were measured by extensometric technique. Theeffect of the yielded region at the notch tip, calculated by elastic-plastic finite elementmodelling of the fatigue tests, was included in the discussion of experimental results. Theimportance of the bi-modal and lamellar microstructure on the material damage wascorrelated to the observed oscillations in the crack growth rate and compared with long crackpropagation data measured using C(T) specimens.