The apical sealing ability of a standard lateral condensation technique was compared with that of two different warm lateral condensation techniques. Sixty extracted human teeth with single canals were instrumented and randomly placed into three groups. Four additional teeth were used as controls. Each group of 20 teeth was obturated with gutta-percha and sealer using one of the three techniques. After 7 days in India ink, the teeth were cleared and the linear extent of ink penetration was measured with a stereomicroscope. No leakage was evident in the two negative controls whereas complete leakage was present in the two positive control teeth. Statistical analysis of the results showed no significant difference in leakage between the experimental groups.