A continuous process for the manufacture of 5-hydroxy methylfurfural (HMF), using a stirred tank reactor with simultaneous reaction and extraction was studied. Methylisobutylketone (MIBK) was used as the extraction agent. The experiments were carried out at elevated temperatures and moderate acidity. Other process parameters were the initial concentration of D-fructose, the residence time, and the ratio of MIBK and H2O. Though the effect of extraction was limited due to the fact that the formation of HMF was faster than its breakdown, the use of MIBK as a cosolvent appeared to have a beneficial influence on the course of the reaction. The productivity at short residence times is lowered due to the stability of intermediate products.