To evaluate the emission behavior of hexabromocyclododecanes (HBCDs) and polybrominated diphenyl ethers (PBDEs) added to textile products as flame retardants, we used a small stainless steel container (7 cm i.d. × 5.5 cm height, ca. 210 cm(3)) to conduct emission tests on three upholstery textile samples at temperatures of 20, 40, 60, and 80 °C. The textile samples, which were intended for use in curtain manufacture and had been treated with either technical HBCD or technical DecaBDE, emitted HBCDs and PBDEs, including BDE 209, even at room temperature (20 °C), and the emission rates increased with increasing test temperature. These results indicate that flame-retardant-treated upholstery textiles have the potential to be major sources of brominated flame retardant contamination in indoor air and dust. The HBCD diastereomer emission profiles at the test temperatures of 20 and 40 °C were similar to the profiles of the original textile samples; in contrast, at the higher test temperatures, the proportion of α-HBCD was larger (up to 70% of the total HBCD emission) than in the original samples. At the higher test temperatures, the proportions of di- to hexa-BDEs in the emissions were clearly larger than in the original sample, suggesting that the textile products treated with technical DecaBDE could be a source of environmentally relevant PBDE congeners such as BDE 47, 99, and 100. The emission rates of HBCDs from the textiles were two orders of magnitude higher than those of PBDEs, suggesting that HBCDs volatilize more easily from textile products to the indoor environment than PBDEs.