Based on the responses of 5,557 Chinese secondary students in Hong Kong, the relationships among perceived hopelessness, family functioning, and suicidal ideation were examined. Results showed that suicidal ideation was positively related to hopelessness, but negatively related to parent-adolescent communication. Compared with father-adolescent communication, mother-adolescent communication generally had a stronger association with adolescent suicidal ideation. It was further found that the linkage between hopelessness and adolescent suicidal ideation was stronger under a low parent-adolescent communication condition, thus suggesting the moderating effect of parent-adolescent communication on the effect of hopelessness on suicidal ideation. The theoretical and practical implications of the findings are discussed.