The present invention provides a process for producing a 2-acylthiophene compound which has a low content of the 3-isomer generated as a by-product, the process comprising reacting a thiophene compound represented by formula (1): wherein R1is a hydrogen atom, a C1-6 alkyl group, a phenyl group, or a halogen atom, with at least one member selected from the group consisting of acid anhydrides represented by formula (2): wherein R2 is a C1-6 alkyl group or a phenyl group, and acid halides represented by formula (3): wherein R2 is as defined above and X is a halogen atom, in the presence of a solid acid catalyst at a temperature less than 75° C. in the absence of solvent, thus producing a 2-acylthiophene compound represented by formula (4): wherein R1 and R2 are as defined above.