Abstract: The present invention relates to a process for producing potassium formate. Formaldehyde, potassium hydroxide and isobutyraldehyde are reacted in water, at a molar ratio of 1.0:1.0:1.0 to 3.0:2.0:1.0 and at a temperature of 0-1000 C, preferably 30-700 C. The obtained reaction solution is neutralised to pH 4-6 and evaporated in a first step, whereby two phases are obtained, one organic phase and one aqueous phase, the latter comprising the main part of the potassium formate. The organic phase is subsequently separated from the aqueous phase, where after a final evaporation of the aqueous phase takes place at a pressure of 0.0-1.0 bar and a temperature of 160-2500 C, to obtain a melt of potassium formate. Water is added followed by filtration resulting in a solution having a content of >99% by weight of potassium formate, calculated on a water free basis.