Adolescent problems in Hong Kong have brought questions about their moral development and mental health to light. Moral education for preschool children will be strategically important to address these issues because applying early educational interventions to preschool children will effectively enhance their personal development. This article highlights the inadequacy of the Hong Kong preschool curriculum guides in the promotion of moral development in children. The lack of a consensus about the values and character that preschool children should develop is a fundamental problem of implementing preschool moral education in Hong Kong. If moral education is regarded as a school curriculum, either formal or informal, the objectives, content and assessment should be closely adhered to one another. In addition, the learning and teaching activities should also be in line with student's developmental characteristics and experiences. The O-C-A model is then proposed for moral education in the preschool settings of Hong Kong. Advice has also been made for the promotion of moral education in Hong Kong's early childhood settings.