A safety hook includes a main body defining an inner space and an opening, a latch unit pivoted to the main body, an operable unit pivoted to the main body, and a safety lock unit. The latch unit is normally at a closed position for blocking the opening. When the operable unit is pressed, the safety lock unit is co-rotatable with the operable unit with respect to the main body from a locked position, where the safety lock unit abuts against the latch unit to retain the latch unit at the closed position, to an unlocked position, where the safety lock unit is removed from the latch unit to allow the latch unit to rotate from the closed position to an opened position allowing access into the inner space through the opening.