Joint attention is a hallmark of human cognition. It refers to the capacity to coordinate attention to objects and events with attention to other people. Infants display considerable individual differences in this capacity. This longitudinal study of 13-month-old preterms was conducted to examine the hypothesis that two different types of joint-attention skills assessed in an infant–tester paradigm are related to verbal and nonverbal IQ measures through middle childhood. Data are reported separately for the children's tendency to initiate such skills and to respond to an experimenter's offers to share in such behaviours. The results provide support for the hypothesis that the initiation of joint attention makes a unique contribution to later nonverbal IQ apart from variance associated with biomedical risk status and infant development. The results of this study have implications for the conceptualisation of joint-attention skills, as well as for understanding the relation between joint attention and later cognition.