A process for the distillation of an aldehyde mixture comprising a straight-chain aldehyde and a branched-chain aldehyde is described in which the process comprises: supplying a feed comprising the aldehyde mixture to a first separation vessel; operating said first separation vessel at a first temperature and a first pressure such that separation occurs; recovering a first stream comprising the straight-chain aldehyde from said first separation vessel and supplying said first stream to a second separation vessel; operating said second separation vessel at a second temperature and a second pressure such that separation occurs; recovering a product stream comprising the straight-chain aldehyde and a second stream comprising high-boiling components from said second separation vessel, and supplying said second stream to a third separation vessel; operating said third separation vessel at a third temperature and a third pressure such that separation occurs; and recovering a third stream comprising the aldehyde mixture from said third separation vessel and reintroducing said third stream to the first separation vessel.