A fitting (20, 40, 220) for sliding doors and windows comprising: a base member (41) configured to be fixated to a door leaf or a window sash that is rectilinearly displaceable in the first displacement direction along a rail (4, 5) fixated along a frame portion. A guiding member (42, 142) is fixated to the base member and displaceable relative to the base member in a second displacement direction, perpendicular to the first displacement direction. The guiding member has at least one guiding element (50, 150) arranged to guidingly engage with the rail. An activation member (43, 243) is connectable with an espagnolette (7) at the door leaf or window sash and configured to bring about the displacement of the base member relative to the guiding member. The activation member is arranged between the base member and the guiding member and displaceable relative to the base member in the first displacement direction. The activation member has at least one activation slot (54) extending at an angle to the first displacement direction and cooperates with an activation tap (57) fixated to the guiding member and received in an elongated hole (49) in the base member, extending in the second displacement direction. In order to bring about displacement of the base member relative to the guiding member in the second displacement direction, the activation member is displaced relative to the base member in the first displacement direction.