When a Woman Sins is a 1918 American silent drama film directed by J. Gordon Edwards and starring Theda Bara.

As described in a film magazine,[1] nurse Lilian Marchard (Bara) is engaged by Mortimer West (Swickard), an old rogue who is dangerously ill. She meets his son Michael (Roscoe), a divinity student, and his earnestness ignites a spark of love within her.

Michael professes his ardent love for her in the garden, and that night, coming upon her in Mortimer's bedroom, she misconstrues the situation and becomes angry.

Poppea hosts a dinner for several wealthy men and just as she is about to auction herself off to the highest bidder, she receives a bible and lily from Michael.

She gives up her fast friends and returns to the slums to minister to the sick, finally winning Michael's love.