The purpose of this study was to evaluate the sealing ability of Portland cement and MTA in comparison to amalgam as retrograde filling materials by utilizing three different root-end preparatory methods (laser, ultrasonic and conventional techniques). One hundred and twenty eight teeth were used divided into three main experimental groups (n=36): (1) diode laser preparation (L) (980nm 8w/10 sec.), (2) ultrasonic preparation (US) (medium power), and (3) Bur preparation (B)(carbide size ½ in lows peed handpiece). Each group was further subdivided into three subgroups (n=12), Portland cement, MTA and amalgam filling respectively. Twenty samples were used as control; they were divided into three positive control groups each of five samples. The teeth in these groups had retrograde cavities prepared in the same manner but without any retrograde filling. The remaining negative control group (n=5) had root-end resection but without root-end cavity preparation. After root canal instrumentation using step-back technique and obturation using lateral condensation technique, the apical 3mm of each root was resected at 90˚ angle. Microleakage was assessed by dye extraction test. The optical absorbance was measured using a spectrophotometer at 550nm. The results showed that there were no statistically significant differences among samples prepared by ultrasonic and laser methods in preventing microleakage. However, samples prepared using conventional bur method showed less microleakage values than other methods. There were statistically significant differences among samples sealed with different materials (p< 0.05). MTA showed the lowest mean microleakage score, followed by PC then amalgam.