In commercial sawn wood (green lumber) (50 × 150 mm) the pinewood nematode,Bursaphelenchus xylophilus(PWN) was found more frequently and in greater numbers in bluestained sections of lumber boards. The nematode population was dominated by third dispersal juvenile stage (J111). At 70°C a sawmill kiln was more effective in eradicating PWN from infested boards as compared to a laboratory heating oven. In pieces of boards (50 × 150 × 45 mm) all nematodes were killed in 30 minutes in the sawmill kiln, whereas in the laboratory oven, even after 9 hours, living nematodes were present. In 60 cm boards all the nematodes were killed in 2 hours in the sawmill kiln. The results suggest kiln‐heating to be a very effective means of control of PWN in lumber, high temperature being the main contributor to the death of the nematodes. A high frequency of J111of PWN in lumber appeared to be of no importance for this efficiency.