Eight year field efficacy data for two formulations of Termidor resulted with 100% control against subterranean termite invasion into urban homes under field conditions. All structures were built on monolithic concrete slabs and received a full exterior barrier soil treatment and interior treatment if active infestations were found. Applications of Termidor were made at the 0.06% application rate in accordance with the 1998 label recommendations. Tank samples were taken and analyzed by gas chromatography for recovery of parent fipronil. Annually, soil samples were taken and evaluated for parent fipronil by gas chromatography and bioassays were conducted with Reticulitermes flavipes (Isoptera: Rhinotermitidae) to determine efficacy of recovered fipronil.