Abstract: A peak hook includes a pair of spaced-apart, elongated, hook-shaped members in which each of the hook-shaped members has a rear downwardly-depending leg for extending over a rear surface of a roof and a front downwardly-depending leg for extending over a front surface of the roof. A roof-engaging member having a length substantially equal to a width of the ladder attaches to the rear downwardly-depending legs for engaging the rear surface of the roof. A rung-engaging member attaches to the front downwardly-depending legs for supporting portions of a rung adjacent to opposite sides of the ladder. A slidable rung-engaging member having apertures through which respective front downwardly-depending legs extend cooperates with the rung-engaging member to releasably attach the peak hook to the ladder.