Low-cycle fatigue of tin-lead eutectic solder was studied at room temperature. The responding load level under cyclic strain was found to decrease continually with number of cycles and this behaviour was described by a constitutive equation. No significant difference in fatigue behaviour was observed between the tests with R=-1 and R=0 (R=epsilon(min)/epsilon(max)) under the same strain amplitude, and this was attributed to the high level of plastic strain produced. Multiple initiation of fatigue cracks was promoted by slip bands developed on the surface of the specimen.