The Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), was probably introduced into the United States from China with solid wood packing and dunnage during the 1980s, and it has recently become established in limited infestations near several major cities in the United States. Regulated wood packing material (RWPM) arriving in the United States from China is required to undergo fumigation with methyl bromide (MeBr), to be heat treated, or kiln dried. Sulfuryl fluoride (SF) is a candidate fumigant to replace MeBr under certain conditions. SF fumigations were conducted in 432-liter Lexan chambers held in a 6.1-m (20-foot) refrigerated container for temperature control. Each fumigation consisted of 12 Populus spp. 10- by 10- by 115-cm timbers, of high moisture content, naturally infested with Asian longhorned beetle. During 2001, we fumigated wood for 24 h at a range of doses (20–112 g/m³) and temperatures (4.4, 10.0, 15.6, and 21.1°C) and subjected the data to probit analysis. Confirmatory fumigations were conducted at doses of 120 and 104 g/m³ at temperatures of 10.0 and 15.6 or 21.1°C, respectively, which resulted in complete kill of all larvae. Pupae that became available later in the year as temperatures warmed were fumigated at 15.6 and 21.1°C with 104 g/m³, which resulted in complete pupal mortality. The next year (2002), we conducted 24-h fumigations with doses of 116 g/m³ at 4.4 and 10.0°C with cold-harvested wood infested with cold-acclimated larvae. Cold-acclimated larvae required much higher concentration times time (CxT) product for control at 4.4 and 10.0°C compared with nonacclimated larvae. Sulfuryl fluoride treatments at a dose of 104 g/m³ and temperature of 15.6°C and above and that achieved a CxT product of 1,095 g-h/m³ or above are recommended for RWPM infested with Asian longhorned beetle larvae and pupae.