The present invention relates to a process for preparing hydroformylation products of olefins having at least four carbon atoms, in which a high proportion of both the linear C.sub.i-olefins having a terminal double bond comprised in the olefin-comprising feed used and of the linear C.sub.i-olefins having an internal double bond is converted into hydroformylation products. Furthermore, the invention relates to a process for preparing 2-propylheptanol which comprises such a hydroformylation process.