A wireline sealing assembly adapted to seal a line such as wireline or slickline deployed in an oil or gas well has a body to receive a line and a seal adapted to be actuated into sealing engagement with the line to contain wellbore pressure within the well below the actuated seal. The seal comprises first and second seal members, each seal member comprising at least one sealing element, wherein the first and second seal members are formed of different materials. The second seal member may have a greater hardness rating or lower degree of resilience that the first seal member. The first and second seal members may radially deform against the line when the seal is actuated, and the first seal member may radially deform more than the second seal member. The seal may also comprise a third seal member comprising at least one sealing element, wherein the third seal member is formed of a different material to the first and second seal members.