The purpose of the study is to investigate whether it is economically profitable to implement a paid period leave for women with severe menstrual pain in Sweden. In order to evaluate the economic effect of such legislation, a cost benefit analysis is conducted where benefits are weighed against costs in monetary terms. This study will only concern employed women in Sweden of childbearing age between 20–54 years who theoretically could experience severe menstrual pain. The data has been taken from Socialstyrelsen, Statistiska centralbyrån, Försäkringskassan, Skatteverket, Statens beredning för medicinsk utvärdering, Tandvårds- och läkemedelsförmånsverket as well as from other relevant studies. In total, the net present value of a three-day paid menstrual leave amounted to approximately SEK 3,84 billion, and the benefit-cost ratio amounted to 1.10. As the benefit-cost ratio is close to one, it becomes difficult to make a recommendation for or against the implementation of a three-day paid period leave for employed women in Sweden.