|Abstract||BACKGROUND: Effective therapeutic protocols for the treatment of pubic lice include application of approved insecticidal products to all body and scalp hair, retreatment at seven days, and use of mechanical removal of lice and eggs. OBJECTIVE: We report here infection with pubic lice in a 43 year old male in Australia which failed to be eradicated by adequate therapy with a pyrethrin and piperonyl butoxide product. DISCUSSION: Pubic lice collected from the case survived after exposure to the same product in vitro. The infestation was cured by use of 5% permethrin. This appears to be the first report of Pthirus pubis resistant to insecticides, in this case pyrethrins and their synergist, piperonyl butoxide.