The invention relates to a method in rope condition monitoring of an elevator, in which method at least the following steps are performed: electrical resistance between a first point and a second point of elevator suspension and/or transmission ropes is measured first time, a threshold value is determined based on the measurement, the elevator is used for transporting passengers and/or goods, electrical resistance between the first point and the second point of said suspension and/or transmission ropes is measured second time, and results of said second time measurement are compared with said threshold value, and if said second time measurement meets said threshold value, predetermined actions are carried out. The invention also relates to an arrangement in rope condition monitoring of an elevator.