This article reviews the currently available collagen injectable fillers and describes injection techniques. Collagen was one of the first fillers for aesthetic enhancement and has been in use for more than 20 years. In recent years there has been a surge of new injectable fillers, with more anticipated in the near future. Despite the large number of new products for augmentation and wrinkle filling, there still remains a role for injectable collagen--alone and in combination with other wrinkle fillers.