Abstract: The present invention relates to a process for preparing polyamines having a mean molecular weight of ?203 g/mol, in which the deviation from the mean molecular weight per ° C. of change in the reaction temperature is <19% of the mean molecular weight, by polycondensation of diamines in the liquid phase in the presence of heterogeneous catalysts based on transition metals of the eighth to eleventh transition groups of the Periodic Table of the Elements and hydrogen at temperatures of 100 to 250° C. and pressures in the range from 60 to 150 bar, to the polyamines obtainable by this process, and to the use of the polyamines.