This　paper　presents　a　fatigue　assessment　model　that　was　developed　for　corroded　reinforced　concrete　(RC)　beams　strengthened　using　prestressed　carbon　fiber-reinforced　polymer　(CFRP)　sheets.　The　proposed　model　considers　the　fatigue　properties　of　the　constituent　materials　as　well　as　the　section　equilibrium.　The　model　provides　a　rational　approach　that　can　be　used　to　explicitly　assess　the　failure　mode,　fatigue　life,　fatigue　strength,　stiffness,　and　post-fatigue　ultimate　capacity　of　corroded　beams　strengthened　with　prestressed　CFRP.　A　parametric　analysis　demonstrated　that　the　controlling　factor　for　the　fatigue　behavior　of　the　beams　is　the　fatigue　behavior　of　the　corroded　steel　bars.　Strengthening　with　one　layer　of　non-prestressed　CFRP　sheets　restored　the　fatigue　behavior　of　beams　with　rebar　at　a　low　corrosion　degree　to　the　level　of　the　uncorroded　beams,　while　strengthening　with　20-　and　30%-prestressed　CFRP　sheets　restored　the　fatigue　behavior　of　the　beams　with　medium　and　high　corrosion　degrees,　respectively,　to　the　values　of　the　uncorroded　beams.　Under　cyclic　fatigue　loading,　the　factors　for　the　strengthening　design　of　corroded　RC　beams　fall　in　the　order　of　stiffness,　fatigue　life,　fatigue　strength,　and　ultimate　capacity.