AyounggirlbythenameofJohnsyhasfallenillandisdyingofpneumonia.Shewatchestheleavesfallfromavineoutsidethewindowofherroom,anddecidesthatwhenthelastleafdrops,shetoowill"drop,"anddie.WhileSuetriestotellhertostopthinkinglikethat,Johnsyisdeterminedtodiewhenthelastleaffalls.
AnoldFrenchman,namedBehrman,isanartist(andaverybadonetoo)wholivesnearbyandisSue'stutor,andwhohasbeenclaimingthathewillpaintamasterpiece,eventhoughhehasneverevenattemptedtostart.Suegoestohim,andtellshimthathersisterisdyingofpneumonia,andthatJohnsyclaimsthatwhenthelastleaffallsoffofavineoutsideherwindow,shewilldie.Behrmanscoffsatthisasfoolishness,butdecidestoseeJohnsyandthevine.
Inthenight,averybadstormcomesandwindishowlingandrainissplatteringagainstthewindow.SueclosesthecurtainsandtellsJohnsytogotosleep,eventhoughtherewerestillfourleavesleftonthevine.JohnsyprotestsbutSueinsistsondoingsobecausedoesn'twantJohnsytoseethelastleaffall.Inthemorning,Johnsywantstoseethevine,tobesurethatalltheleavesaregone,buttotheirsurprise,thereisstilloneleafleft.
WhileJohnsyissurprisedthatitisstillthere,sheinsistsitwillfallthatday.Butitdoesn't,nordoesitfallthroughthenightnorthenextday.Johnsybelievesthattheleafstayedtheretoshowhowwickedshewas,andthatshesinnedinwantingtodie.Sheregainsherwilltolive,andmakesafullrecoverythroughouttheday.
Intheafternoon,adoctorcomesandtalkstoSue.ThedoctorsaysthatMr.Behrmanhaddiedofpneumoniaanhourago,andthathewasillonly2days.Ajanitorhadfoundhimhelplesswithpain,andhisshoesandclothingwerewetandicycold.Thejanitorcouldn'tfigureoutwherehehadbeenonthatstormynight,thoughshehadfoundalanternthatwasstilllit,aladderthathadbeenmoved,somescatteredbrushes,andapalettewithgreenandyellowcolorsmixedonit."LookoutthewindowSue,doyouseethatlastivyleaf?Darling,thatwasBehrman'smasterpiece-hepaintedittherethenightthatthelastleaffell."