Previous research has shown that children with high levels of early anxiety/withdrawal are at increased risk of later anxiety and depression. It has also been found that positive parent–child attachment reduces the risk of these disorders. The aim of this paper was to examine the extent to which positive parent–child attachment acted to mitigate the risk of later internalising disorders amongst children with high levels of early anxiety/withdrawal using data from a 30 years longitudinal study of a New Zealand birth cohort. The findings of this study showed that: (a) increasing rates of early anxiety/withdrawal were associated with an increased risk of later anxiety and depression; (b) positive parent–child attachment in adolescence was associated with a decline in the risk of later anxiety and depression; and (c) these associations persisted even after controlling for confounding factors. The implications of these findings for the role of parent–child attachment in mitigating the adverse effects of early anxiety/withdrawal are discussed. It is concluded that positive parent–child attachment in adolescence may act as a compensatory factor which buffers the adverse effects of childhood anxiety/withdrawal on risks of developing later anxiety and depression.