Courtship, which usually occurs between February and March, and reportedly simply consists of a soaring flight above the breeding area. The Steller's sea eagle copulate on the nest after building it. They lay their first greenish-white eggs around April to May. The eggs range from height and in width and weigh around , being slightly larger than those of harpy eagles. Clutches can contain from one to three eggs, with two being the average. Usually, only one chick survives to adulthood, though in some cases as many as three will successfully fledge. After an incubation period around 39 – 45 days the chicks hatch. The chicks are altricial and covered in whitish-down on hatching. The eaglets fledge in August or early September. Adult plumage is attained at four years of age, but first breeding does not typically occur for another year or two.