The effect of parent-child communication on the mental health condition was examined by questionnaire response from 758 junior high school students. The scores indicating communication with the father were significantly lower than those for communication with the mother. Low scores were seen in the answers to the questions “I think I can tell my father how I really feel about something, ” “If I were in trouble, I could tell my father, ” and “I openly show affection to my father.” The scores for communication with the father were significantly correlated with the mental health condition of the students, with high correlation being found for the questions “I think I can tell my father how I really feel about something, ” “If I were in trouble, I could tell my father, ” and “When I ask questions, I get honest answers from my father.” Communication discrepancy, in the case of a student giving a negative answer and the father giving a positive answer to the same question, affected the mental health condition. Communication consistency, in the case of both a student and father giving a negative answer to the same question gave the lowest scores for the mental health condition. Communication discrepancy, in the case of a student giving a negative answer and the mother giving a positive answer to the same question, also affected the mental health condition; however the number of cases of this type of discrepancy with the mother was less than that discrepancy with the father.