A method of producing monocyclic aromatic hydrocarbons includes bringing a light feedstock oil having a 10 vol % distillation temperature of 140° C. to 205° C. and a 90 vol % distillation temperature of 300° C. or lower, which has been prepared from a feedstock oil having a 10 vol % distillation temperature of 140° C. or higher and a 90 vol % distillation temperature of 380° C. or lower, into contact with a catalyst for monocyclic aromatic hydrocarbon production containing a crystalline aluminosilicate, in which a content ratio of monocyclic naphthenobenzenes in the light feedstock oil is adjusted by distillation of the feedstock oil such that the content ratio of monocyclic naphthenobenzenes in the light feedstock oil is higher than a content ratio of monocyclic naphthenobenzenes in the feedstock oil.