The application of thermomorphic solvent systems offers the combination of homogeneous catalysis in a single phase and catalyst recovery via phase separation. To increase economic feasibility the minimization of waste streams and side reactions is desired. For this, a continuous process for the hydroformylation of 1-dodecene in the solvent system DMF/n-decane is shown. While the Rh/Biphephos catalyst is recycled in DMF in a first loop, the n-decane and remaining olefins are separated from the product via distillation to form the second loop. In this process the need for additional solvent supply and the isomerization reaction of 1-dodecene is reduced significantly. The reaction toward internal olefins decreases from initially 15 to 3%. The stable hydroformylation process with a yield of the linear hydroformylation product of 55% and l/b-ratio of 95/5 is shown for 120 h. (c) 2016 American Institute of Chemical Engineers AIChE J, 62: 4377-4383, 2016