This paper reviews the literature on sleep problems in pre-school children, aiming to raise awareness of the current knowledge in this field. The article begins with a discussion of the prevalence of sleep problems in young children. Disorders of initiating and maintaining sleep are by far the most common type of sleep problem in this age group, and are therefore the focus of this review. The effects of sleep disturbance are examined, focusing on how parents often feel desperate and in need of support outside the family. The causes of sleep problems are considered and the complexity in identifying causal factors is highlighted. The article continues with an exploration of the treatment of sleep problems, suggesting that much of the advice given to parents is contradictory. The literature demonstrates that the use of medication is common, but it appears that this method of treatment is of limited benefit. It seems that behaviour modification or a psychodynamic approach may be much more successful, and the use of self-help manuals/booklets has been shown to be useful by some authors. Finally, preventative strategies are discussed highlighting the need for further research in this area.