A purification process for cyclic formals, in which water is efficiently removed from a crude cyclic formal, namely, a mixture of a cyclic formal and water which is difficult to be separated from the mixture, thereby obtaining a cyclic formal of high purity which contains only a very small amount of water.The purification process for cyclic formals is characterized by the steps of supplying a mixture of a cyclic formal and water into a distillation tower, effecting distillation while supplying a hydrophilic solvent (A) having a boiling point from 180.degree. to 250.degree. C. into the distillation tower at a position higher than the supply position of the mixture, and taking out a purified cyclic formal as a distillate.