The heartwood of western redcedar (Thuja plicuta) is known for its natural resistance to fungal attack, but some users of western redcedar utility poles have suggested that its durability may be diminished as suppliers begin to harvest trees from younger stands. The decay resistance of western redcedar samples from the Pacific Northwest and Idaho was tested by using Postia placenta in a soil block test. Weight losses varied widely among and between sites and were not correlated with position in the heartwood cross section, tree age, or silvicultural factors. With results similar to those from a 1957 study, we can infer that the durability of the currently used younger material has not changed from that of earlier, older stocks.