To produce a prostaglandin E in a short time and in a high yield while minimizing the formation of isomers. A process for producing a prostaglandin E represented by general formula (I) wherein A represents an arbitrary group not participating in the reaction; B represents vinylene or ethynylene; R⁴ and R⁵ may be the same or different from each other and each represents hydrogen or a protective group for a hydroxyl group; and R⁶ and R⁷ represent each an arbitrary group not participating in the reaction, which comprises reacting an allyl ester of a prostaglandin E represented by general formula (II) wherein R¹ and R² may be the same or different from each other and each represents hydrogen or lower alkyl; R³ represents hydrogen, lower alkyl, alkenyl or aryl; and R⁴, R⁵, R⁶, R⁷, A and B are each as defined above, with one or two compounds selected from the group consisting of bases and formic acid in the presence of a complex compound or a complex salt of 0-valent or divalent palladium atom.