The effect of tetracycline hydrochloride as an endodontic irrigant on smear layer removal was examined by scanning electron microscopy and compared with bidistilled water, 2.5% sodium hypochlorite (NaOCl), and 50% citric acid in 20 extracted teeth. Five teeth, as a control, were irrigated with bidistilled water only in group 1. All the other groups were irrigated with NaOCl during instrumentation. The final rinses were NaOCl in group 2, citric acid in group 3, and 1 % tetracycline hydrochloride in group 4. Scanning electron microscopic results and statistical analysis revealed that bidistilled water and NaOCl were ineffective in removing the smear layer, whereas citric acid and tetracycline hydrochloride were significantly more effective (p < 0.001). No statistically significant difference was detected between tetracycline hydrochloride and citric acid (p > 0.05). However tetracycline hydrochloride demineralized less peritubular dentin.