Magnetic susceptibility, electrical resistivity and thermoelectric power measurements on new rare earth ternary intermetallic R2Mn3Si5 (R = Dy, Ho and Er) compounds crystallizing in the Sc2Fe3Si5-type tetragonal crystal structure were carried out in the temperature range 15-300 K. Dy- and Ho-based alloys show two successive magnetic transitions (Dy2Mn3Si5 at 76 and 32 K; Ho2Mn3Si5 at 67 and 19 K) and the Er-based compound undergoes a magnetic transition around 55 K. The electrical resistivity is ferromagnetic metal-like, displaying typical low temperature T2 dependence and a high temperature spin-disorder contribution. Thermoelectric power is negative at room temperature, crosses zero and has a broadened peak feature centered around 50 K indicating a phonon drag effect at low temperatures and it does not have the signature of magnetic ordering. The successive magnetic transitions are suggestive of the presence of competing magnetic interactions in these systems. © 2001 Elsevier Science B.V.