Accumulation rates of manganese in sediments of thirty-eight deep-sea cores range from 0.1 to 3.4 mg/cm²/ka. Manganese accumulation rates in five nodules range from 0.2 to 1.0 mg/cm²/ka. In the North Pacific, manganese is apparently incorporated into sediments in association with clay or a related phase; in other ocean basins, no generalizations can be drawn from the data presented here. The similarity between nodule and sediment manganese accumulation rates could be coincidence or could reflect the possibility that nodules and sediments accumulate manganese by the same mechanism.