Introduction: The aim of the present study was to compare two obturation techniques, i.e. Thermafil® and cold lateral condensation, in order to determine which one was most easily and rapidly learnt and applied by dental students. Methods: Fifty single-rooted teeth were instrumented by the crown-down technique. Five students were requested to obturate five teeth using the Thermafil technique and five using lateral condensation. A microleakage study was performed using a 2% aqueous methylene blue dye solution. The apical portion of teeth was sectioned into six sections and evaluated under a stereomicroscope. The presence of dye microleakage was considered when assessing every section. Results: Results were processed statistically by frequence of distribution and the Mann-Whitney test. A highly significant difference (P 0.0001) was observed between Thermafil and cold lateral condensation techniques, the former resulting in lower leakage. Conclusion: The present study, though limited and only referring to a small group, suggested that characteristics of operators and the early repeated use of a technique may influence performance. Keywords: education, filling techniques, lateral condensation, Thermafil