This automatic bicycle pedal comprises a pedal body (2) equipped at a first end (5) with first attachment means (7) and at a second end (6) with second attachment means (10), an elastically deformable lever (8) bearing the second attachment means and capable of being deformed between a first position of holding a cleat fixed to the underside of a shoe between the first and second attachment means, and a deformed second position allowing the cleat to be attached and detached in respect of attachment and detachment movements. The deformable lever comprises at least one first deformable zone (12) that can be deformed during attachment and detachment movements and at least one second deformable zone (13) that can be deformed during one of the said attachment and detachment movements, the said first and second zones having different stiffnesses.