Proplast is an ultra-porous composite material that has been used widely to augment the facial skeleton. In recent years, however, the popularity of this material has declined because of complications associated with its use. This paper presents a retrospective study of 36 cases treated with 88 Proplast implants at one unit over a nine-year period. The results suggest that infection of the implant is the most common post-operative complication. Infection may occur at any time following implantation and appears to be more likely when implantation is associated with an osteotomy procedure. In addition, the overall rate of infection in this study (16%) was higher than reported previously and the male-female ratio was 2:1. The possible factors involved in infection are discussed.