A pyrazole compound represented by general formula (1) is reacted with a sulfur compound represented by general formula (2) in the presence of a base and formaldehyde, to thereby produce a 5-hydroxy-4-thiomethylpyrazole compound represented by general formula (3). The 5-hydroxy-4-thiomethylpyrazole compound may easily be produced in a good yield, by using such a process. Further, this process may easily provide the 5-hydroxy-4-thiomethylpyrazole compound under a mild condition in a single step, without using a special apparatus, an expensive catalyst, or a transition metal, etc. In addition, this process may be conducted substantially without producing a harmful waste which can be derived from a catalyst, etc., and therefore this process is friendly to the environment and industrially valuable.