Abstract: A lifeline support device for being mounted on a scaffold frame having a vertical member and a horizontal arm connected to the vertical member, including a tubular support post base, and a support post securable in the support post base. The support post base has a hook engageable over the horizontal arm, a pipe receiver engageable with the vertical member and a clamp detachably mounted to a lower portion of the tubular support post base for clamping the vertical member, while the support post has a proximal portion fittable into the tubular support post base and a distal portion provided with a ring for receiving a lifeline.