The increased surface roughness of dental implants has shown enhanced integration of bone tissues to implant surfaces, but may be predisposed to an increased risk of pathogenic bacterial infection and contamination with bacterial products. Tetracycline-HCl (Tc) treatment has been regarded as a practical and effective chemical modality for decontamination and detoxification of contaminated implant surfaces. The purpose of this study was to examine if Tc treatment alters the microstructures of the modified surface of dental implants. For this purpose, dental implants with pure titanium machined surface (MS), sandblasted, large grit, acid-etched surface (SLAS), or anodized surface (AS) were used. The surface of dental implants was rubbed for 30, 60, 90, 120, or 150 sec with sponge pellets soaked in Tc solution (50mg/ml) and in distilled water for 0 and 150 sec as the control group. The specimens were then routinely processed for scanning electron microscopy. The results show that Tc treatment did not change the surface of MS, SLAS, and AS.