This study was to assess the moderating roles of intrinsic value in the relation of basic psychological needs support to academic engagement in mathematics. We recruited 246 middle school students by using the Basic Psychological Needs Support Scale, the Intrinsic Value Scale and the Academic Engagement Scale. This study found that both basic psychological needs support and intrinsic value had significant predictions on the three aspects of academic engagement. Moreover, the interaction item between basic psychological needs support and intrinsic value could significantly affect emotional and cognitive engagement, but not behavioural engagement. The findings indicated that except for behavioural engagement, the associations between basic psychological need support and emotional or cognitive engagement could be moderated by intrinsic value. This study provides a special perspective for educators and researchers to recognise the role of intrinsic value in promoting adolescents' higher levels of involvement in mathematics class.