A method for producing a 3-hydroxy nitrogen-containing six-membered cyclic compound is provided. Namely, microbial cells of a microorganism and/or a preparation obtained from the microbial cells is allowed to act on a nicotinic acid derivative or a 2-pyrazinecarboxylic acid derivative represented by the following general formula: ##STR1## wherein R.sub.1 and R.sub.2 may be the same or different, representing hydrogen atom, halogen atom, hydroxyl group, amino group, carboxyl group, cyano group, oxime group, or alkyl group having a number of carbon atom or atoms of 1 to 5 respectively, and A represents carbon atom or nitrogen atom, the microbial cells and/or the preparation obtained from the microbial cells having an ability to perform hydroxylation of the nicotinic acid derivative or the 2-pyrazinecarboxylic acid derivative accompanied by decarboxylation of carboxyl group.