Perfectionism, defined by a person’s tendency to set excessively high performance standards and endorsing overly critical self-evaluation, has been seen as a risk factor leading to one’s negative affect and copings (O’Connor, Rasmussen & Hawton, 2009). Despite that maladaptive perfectionism had been widely studied in the clinical and developmental literature, as yet not much is understood in terms of how it relates to family co-rumination behaviours. In view of this, this study recruited 200 community adolescents aged ranged between 9-15 y.o. in Hong Kong and tested if 1) youths’ maladaptive perfectionism was related to co-rumination practices in their families and 2) parenting style could modulate such relationship. Self-report questionnaires including the Frost Multidimensional Perfectionism Scale (FMPS), Modified Co-rumination Questionnaire (CoQ) and Parental Bonding Instrument (PBI) were administered and correlational analyses indicated a significant association observed between perfectionism (FMPS-personal standard subscale) and co-rumination in the family (i.e. youths co-ruminating with parents on parents’ problems). In addition, parental bonding moderated this relationship such that youths living in families with low care and high controlling behaviours had the strongest association observed. Clinical implications are discussed, particularly in relation to the role of parental education on risk prevention and fostering youth’s psychological wellbeing.