Attention-deficit/hyperactivity disorder (ADHD) is defined on the basis of developmentally inappropriate inattention, motor activity and impulsivity that emerges early in development and causes impairment in social and academic functioning. ADHD is described as a multifactorial disease, with a well studied genetic vulnerability, and early environmental factors also playing an important role in the development and course of the disorder. Current aetiological models emphasize interaction between genes and environment. The concept of attachment, as proposed by John Bowlby, reflects quality of early interactions, and should therefore be considered as an early developmental factor. First, clinical findings emphasize similitude between both disorders; emotional dysregulation is an important feature in reactive attachment disorder as well as in ADHD. Emotion regulation is highly related to attachment security in young children and could play a part in the development of early attention processes. Moreover, difficult temperament is associated with higher risk for ADHD on the one hand, and can disturb the process of attachment on the other. Parental caregiving - including maternal sensitivity, positive parenting practices - is a main factor involved in the development of attachment, and has shown to be associated with better outcomes in ADHD children, especially with less oppositional/conduct disorders. Second, the aim of our review is to present clinical studies that have looked for a link between ADHD and attachment: the type of attachment could play a part in the course of the disorder: insecure and disorganised attachment types tend to be associated with a higher risk of externalised behaviors in children. For ADHD, this effect seems to be weaker than for other externalised disorders, and has been shown only in populations of at-risk children. Clinical studies also raise the question of possible links between reactive attachment disorder and ADHD. In children suffering severe early deprivon such as institution-rearing, inattention/hyperactivity symptoms were shown to be high, but these findings may not be valid in less severely deprived children. Third, another link could depend on a common vulnerability for ADHD and attachment disorder. Some perinatal factors, such as smoking during pregnancy or prematurity, have been shown to increase the risk of hyperactive symptoms in children. These variables may also be associated with a higher risk of impaired early interactions. Recent animal studies have raised interest in the role of prenatal stress in the emotional and behavioral development of the offspring, particularly as regards vulnerability to stress. Epigenetic mechanisms may be involved in durable alterations of the hypothalamo-pituitary-adrenergic axis. Preliminary findings in humans show that prenatal stress or maternal depression may also influence the development of the child. The understanding of the relationship between attachment and ADHD may help to better target prevention and intervention efforts. As the perinatal period seems to be particularly involved in both ADHD and attachment disorders, early guidance and possibly prenatal interventions should be developed and assessed for mothers and caregivers with risk-factors.